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1
Theory of quantum devices in the ultra-strong light-matter coupling regime
Domaines
Condensed matter
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Type de stage
Théorique, numérique Contact
Yanko Todorov
20/11/2024
/
Thèse :
Rémunération :
2
Quantum devices in the ultra-strong light-matter coupling regime
Domaines
Condensed matter
Type de stage
Expérimental Contact
Yanko Todorov
20/11/2024
/
Thèse :
Rémunération :
3
Entanglement distribution in the Paris quantum testbed
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Expérimental et théorique Description
Central to the development of long-distance quantum communications is the concept of quantum repeater. It consists in dividing a long communication channel into various shorter segments over which entanglement can be faithfully distributed. Adjacent segments are then connected by entanglement swapping operations. To be scalable, this approach requires quantum memories, which enable quantum states to be stored at each intermediate node.
In this context, the LKB team has been developing non-degenerate sources of entangled photon pairs compatible with both telecom networks, and an atomic quantum memory. This quantum memory based on a cold atomic ensemble in the group enables qubit storage with an overall efficiency close to 90% mark for entanglement storage between two memories.
The work is now focusing on two directions. A first one is to improve the figures of merit, including the efficiency, and to interface it with an atomic quantum memory. A second one is the implementation of quantum networking protocols, from photonic teleportation on a dedicated fiber network on the Jussieu campus, to the demonstration of a 50-km telecom quantum repeater link relying on two distant quantum memories and frequency non-degenerate photon pair sources. Part of the work will be led in collaboration with the startup company Welinq.
Contact
Alban Urvoy
15/11/2024
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Thèse :
Rémunération :
4
Waveguide-QED - combining cold atoms and nanophotonics (2 internships)
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Expérimental et théorique Description
Controlling light-matter interaction at the single-quantum level is a long-standing goal in optical physics, with applications to quantum optics and quantum information science. However, single photons usually do not interact with each other and the interaction needs to be mediated by an atomic system. Enhancing this coupling has been the driving force for a large community over the past two decades.
In contrast to the cavity-QED approach where the interaction is enhanced by a cavity around the atoms, strong transverse confinement in single-pass nanoscale waveguides recently triggered various investigations for coupling guided light and cold atoms. Specifically, a subwavelength waveguide can provide a large evanescent field that can interact with atoms trapped in the vicinity. An atom close to the surface can absorb a fraction of the guided light as the effective mode area is comparable with the atom cross-section. This emerging field known as waveguide-QED promises unique applications to quantum networks, quantum non-linear optics and quantum simulation. Recently, the LKB team pushed the field for the first time into the quantum regime by creating an entangled state of an array of atoms coupled to such a waveguide. Two experiments are dedicated to this waveguide-QED effort and internships/PhD projects are proposed on both of them.
Contact
Alban Urvoy
15/11/2024
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Thèse :
Rémunération :
5
Quantum simulation with photons in nonlinear waveguide arrays
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Type de stage
Expérimental et théorique Description
Combining the generation and manipulation of complex quantum states of light on a single chip is a crucial step toward practical quantum information technologies. In this internship/PhD project, we will address this challenge by merging two fundamental concepts —nonlinear optics and quantum walks— to realize a compact and versatile source of spatially entangled states of light, and harness them for quantum simulation and quantum state engineering tasks. For this we will tune the coupling between waveguides to implement various lattice geometries, allowing to implement the quantum Fourier transforms of entangled states, Anderson localization in a quasi-periodic potential, or the topological protection of quantum states of light in the Su-Schrieffer-Heeger model. This opens up the stimulating perspective to simulate with photons physical problems that are otherwise difficult to access in condensed matter systems.
Contact
Florent BABOUX
13/11/2024
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Thèse :
Rémunération :
6
Experimental many-body physics with quantum emitters in a photonic lattice
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
The coupling of one or several quantum emitters to the optical modes of a photonic lattice opens up new opportunities to engineer exotic sources of quantum light and to develop novel types of quantum simulators with long range interactions. It would allow studying strongly correlated phases of light in a lattice.
The main goal of this internship is to develop one of the first experimental systems for lattice quantum electrodynamics using molecular quantum emitters. We are currently fabricating an open cavity system with embedded nanocrystals, each with a single quantum emitter. The open cavity is made of two mirrors brought in close proximity (about 1 micron apart) with the use of dedicated piezo actuators. One of the mirrors has been etched using focus ion beam technology to engineer lattices of hemispheric cavities, which define a photonic lattice. The coupling of the quantum emitters to the photonic lattice modes is expected to result in the emergence of non-classical states of light with spread entanglement.
The internship will consist in the alignment and characterization of the open cavity with quantum emitters and the study of the temporal dynamics and quantum properties of the light emitted by the emitters in the lattice. We will use a fully developed experimental set-up with a streak camera and photon counters.
Contact
Alberto Amo
12/11/2024
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Thèse :
Rémunération :
7
Continuous superradiant laser with a laser-cooled atomic beam
Domaines
Quantum optics/Atomic physics/Laser
Quantum optics
Quantum gases
Metrology
Type de stage
Expérimental Description
Recently, a new type of clock has been proposed: the active clock using superradiant lasing. Instead of shining a very stable laser onto ultracold atoms to probe the atom resonance frequency (and thus measure time), the clock would operate by letting the atoms themselves emit light. The light coherence will be set by a collective synchronization of the atomic dipoles with each other - a process called superradiance. Thus, in addition to its significance as a new clock architecture, this system is interesting from a fundamental point of view: it is an example of an open-dissipative system in which correlations of quantum nature may naturally arise.
We have built a prototype for such a cold-atom-based superradiant laser. We want to tackle the unresolved issue of sustaining continuously a superradiant emission. The construction of the apparatus is completed. Throughout the PhD project, we will investigate the light properties to understand how the emitters synchronize their oscillations, and how the light coherence is related to correlations between all atomic emitters. Our experiment will have the unique capability to explore several distinct superradiant emission regimes, that will be identified through the spectral and correlation properties of the light and of the atoms. In collaboration with metrology experts, we will contribute to assessing the metrological interest (i.e., “performance” criteria to act as a clock) of atomic-beam continuous superradiant lasers.
Contact
Martin Robert de Saint Vincent
12/11/2024
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Thèse :
Rémunération :
8
Spin manipulations in a degenerate Fermi gas of strontium atoms
Domaines
Quantum optics/Atomic physics/Laser
Statistical physics
Quantum gases
Type de stage
Expérimental Description
We propose an internship and PhD on degenerate Fermi gases of strontium 87 atoms. This is an exotic fermionic system, in that its spin-9/2 degree of freedom encompasses a large number (10) of Zeeman sublevels. The objective is to explore novel many-body effects (exotic antiferromagnets driven by generalized Fermi-Hubbard model, and "dissipatively stabilized" ferromagnets), and to demonstrate the “technological” opportunity of these quantum objects as a resource for quantum simulation, computation, or sensing.
The idea of a dissipative control is counter-intuitive: dissipation, typically destroying the manifestations of quantum physics, will here actually stabilize quantum states with many-body correlations. This means that quantum phenomena may be harvested for quantum simulation or quantum sensing (clocks, atom interferometers) in a more robust manner than formerly thought.
Our experiments rely on the original spectroscopic properties of strontium: narrow optical lines, relevant to atomic clocks, and that in our case we use to engineer highly selective spin manipulations. We will in the short term use the combined effect of a photo-association laser and of the Pauli principle, to pump the atomic ensemble towards spin-symmetric entangled states. Our objectives will be to characterize these states, test their interest for metrology (e.g. optical clocks desensitized to interaction shifts), and explore new schemes to manipulate the symmetries of the collective spin state.
Contact
Martin Robert de Saint Vincent
12/11/2024
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Thèse :
Rémunération :
9
Probing THz metamaterials with a quantum Rydberg-atom sensor
Domaines
Quantum optics/Atomic physics/Laser
Type de stage
Expérimental Description
The SAI group has developed spectroscopic techniques for probing excited atoms near dielectric planar surfaces and metamaterials.
Metamaterial technology is particularly important for the realization of high-performance devices in the THz (~300µm wavelength) range. However, the characterization of THz metamaterials is carried out in the far field and is limited by diffraction. For this reason, the development of near-field imaging with sub-wavelength resolution has recently become an important area of study.
The SAI group is setting up a new project to probe the near-field of THz micro-resonators using a gas of Rydberg atoms as a quantum sensor. The detection of far-field THz waves has already been demonstrated using Rydberg atoms inside an atomic vapor cell that convert absorbed THz radiation into visible photons. The same technique can provide near-field information, if the atomic vapor is brought into contact with metamaterials. Additionally, this experiment can also be used to demonstrate control the Casimir-Polder Rydberg-metamaterial interaction.
We are therefore proposing a Master’s internship to set up this new experiment. The student will be involved in the construction of a new atomic vapor cell with THz micro-resonators and will perform Rydberg-atom spectroscopy in the vicinity (near-field) of the resonators. This is a collaborative project, with J-M Manceau's group at C2N, specialists in THz devices.
Contact
Athanasios Laliotis
Laboratoire : LPL - UMR7538
Equipe : Spectroscopie Atomique aux Interfaces (SAI)
Site Web de l'équipe
Equipe : Spectroscopie Atomique aux Interfaces (SAI)
Site Web de l'équipe
11/11/2024
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Thèse :
Rémunération :
10
Precision spectroscopy of Casimir-Polder molecule-surface interactions
Domaines
Quantum optics/Atomic physics/Laser
Metrology
Type de stage
Expérimental et théorique Description
The SAI group of the LPL has developed selective reflection and nanocell spectroscopy as two major methods for probing Casimir-Polder interactions with excited state atoms. Using these techniques, the group has pioneered atom-surface interaction studies [A. Laliotis et al., Nature Communications, 5, 4364 (2014), J. C de Aquino Carvalho et al., Phys. Rev. Lett. 131, 143801, (2023)].
The group has now turned its attention to performing the first precision CP measurements with molecules. Molecule-surface interactions are of fundamental interest allowing us to study the chirality of quantum vacuum and Casimir-Polder anisotropy. The SAI group has probed molecular gases close to dielectric surfaces via selective reflection [J. Lukusa Mudiayi et al. Phys. Rev. Lett. 127, 043201 (2021)] or nanocell spectroscopy [G. Garcia-Arellano et al. Nature Communications, 15, 1862 (2024)]. These results allow the study of sub-wavelength confined molecules but have not yet provided a CP measurement.
We are now offering an internship on a new project that aims at probing an HF gas confined inside a nanocell. Our theoretical calculations have revealed HF to be the ideal molecule for CP measurements due to its linear geometry, simplicity and strong transitions at 2,5µm. We are looking for a motivated student to participate in the building of the experiment, detect the first spectroscopic signals and probe Casimir-Polder interactions of HF molecules confined in the nanometric regime.
Contact
Athanasios Laliotis
Laboratoire : LPL - UMR7538
Equipe : Spectroscopie Atomique aux Interfaces (SAI)
Site Web de l'équipe
Equipe : Spectroscopie Atomique aux Interfaces (SAI)
Site Web de l'équipe
11/11/2024
/
Thèse :
Rémunération :
11
Quantum simulation with Strontium circular Rydberg atoms
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Type de stage
Expérimental Description
The purpose of the proposed PhD work is to join our ongoing efforts to build a new experimental platform for manipulating arrays of circular strontium atoms in a cryogenic environment. Our team has recently succeeded in trapping individual ground-state strontium atoms in optical tweezers. The next steps are to transfer strontium atoms into the circular state and recapture them using tweezers tuned close to the optical transition of the ionic core. We will then demonstrate that it is possible to measure the state of the Rydberg atom using selective fluorescence of the second valence electron. During their master’s internship, the student will participate the integration of the setup in a new cryogenic environment and set up a new laser system to improve the fidelity of the preparation of the circular state.
Contact
Sébastien Gleyzes
08/11/2024
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Thèse :
Rémunération :
12
Local THz photons for coherent light-matter interaction
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
This internship is focused on the realization of a frequency converter utilizing the inherent non-linearities of thin film superconductors. In the long term, this on-chip frequency converter will allow the development of a platform for THz spectroscopy at the mesoscopic scale. The goal of the thesis will be to study collective excitations such as magnons in graphene.
Contact
Alexis Jouan
08/11/2024
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Thèse :
Rémunération :
13
Systèmes hybrides quantiques
Domaines
Condensed matter
Type de stage
Expérimental Contact
Marco Aprili
07/11/2024
/
Thèse :
Rémunération :
14
Intégration à grande échelle de matériaux 2D pour des applications quantiques et optoélectroniques
Domaines
Condensed matter
Type de stage
Expérimental Contact
Marco Aprili
07/11/2024
/
Thèse :
Rémunération :
15
Development of Single-photon detectors based on high-Tc superconductors
Domaines
Condensed matter
Type de stage
Expérimental Contact
Marco Aprili
07/11/2024
/
Thèse :
Rémunération :
16
Théorie des circuits quantiques supraconducteurs
Domaines
Condensed matter
Type de stage
Théorique, numérique Contact
Marco Aprili
07/11/2024
/
Thèse :
Rémunération :
17
Stacking photonic graphene sheets: towards 3D polaritonics
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Nouveaux états électroniques de la matière corrélée
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Quantum gases
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
The aim of this project is to study the physics of “synthetic photonic materials”, which consist of synthetic platforms designed in the lab in order to make photons behave like matter particles. In our lab, we use photons trapped in micron-size semiconductor cavity as a building block to realize such materials. For example, by arranging an ensemble of microcavities in the form of a honeycomb lattice, it is possible to create “photonic graphene” structures, which are similar in every respect to the electronic band structure of real graphene.
In this project, we will build upon recent developments in the field of multilayer graphene, to investigate how these concepts transfer to photonic graphene. In particular, how is the band structure of photonic graphene modified when several vertically coupled cavities are stacked? In the presence of a torsion angle between the two layers, what is the impact of the Moiré effect caused by this superposition? Finally, what advantages can be derived from the additional degrees of freedom offered by the photonic platform, for example when the degeneracy between the different polarization states of light is lifted (effective spin-orbit coupling) or when light is coupled to electronic excitations of the semiconductor material?
Contact
Sylvain Ravets
07/11/2024
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Thèse :
Rémunération :
18
Quantum optics in lattices of microcavities
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Nouveaux états électroniques de la matière corrélée
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Quantum gases
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
When shining classical light onto a non-linear medium, intriguing quantum states of light can be generated. In this project, we propose to use lattices of highly non-linear resonators to engineer spatial and temporal entanglement between photons. The work promises to realize a versatile solid-sate platform for implementing and studying quantum many-body phases made out of optical photons.
Contact
Sylvain Ravets
07/11/2024
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Thèse :
Rémunération :
19
Quantum dot fluorescence and optomechanical coupling
Domaines
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
The emission of colloidal quantum dots is highly dependent on their environment. Placed between two layers of gold, and excited in UV light, their emission couples with surface plasmons and its dynamics is accelerated. The smaller the gap between the two gold layers, the more the emission is modified. We propose to actively modify the spacing between the two layers in order to modify quantum dot emission.
We will use the transient grating method, which involves exciting the sample with two infrared laser beams (exc =1064nm; 30ps pulse duration) to produce interference bangs with a period . Through photoelasticity, the standing waves thus created cause the sample to vibrate, modulating its thickness.
The aim of the internship will be to study how the acoustic wave thus created modifies the properties of the light emitted.
The first step will be to produce the samples. After depositing an optically thick layer of gold on a glass subtrate, a solution of CdSe/CdS quantum dots will be deposited. This emitter layer is then covered by a thin layer of gold. Secondly, this layer will be optically characterized under a microscope, both to characterize its thickness in white light and the fluorescence of the quantum dots under UV illumination. Finally, we'll use the transient grating method to change the thickness of the sample. Both thickness and quantum dot fluorescence will be studied.
Contact
Agnes MAITRE
07/11/2024
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Thèse :
Rémunération :
20
Quantum information theory internship at Quandela
Domaines
Quantum optics/Atomic physics/Laser
Quantum Machines
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Théorique, numérique Activité en entreprise
Description
We are excited to offer internships at Quandela, where you'll work on cutting-edge quantum computing projects with top scientists. We have internship topics ranging from quantum error correction, benchmarking of quantum device, error mitigation of photonic quantum computers to quantum algorithms.
Open to students in Physics, Math, Computer Science, and related fields, this 4-6 month internship offers hands-on experience in photonic quantum computing. Apply until November 24th for a chance to join our team!
Apply here: https://apply.workable.com/quandela/j/456A2DC755/
Contact
Pierre-Emmanuel Emeriau
06/11/2024
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Thèse :
Rémunération :
21
Optomechanical nanoscale quantum sensing
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental Description
Optomechanics, the interaction between light and mechanical oscillators, is a burgeoning field
of research at the interface of quantum optics, mesoscopic physics and mechanical micro/nano
systems. Using light, it has recently been possible to control and read-out the quantum states of
mesoscopic mechanical resonators. This has been notably achieved with nano-optomechanical
disk resonators (see image below) fabricated in our team, where the simultaneous
confinement of light and mechanical motion in a sub-micron volume enables strong
optomechanical interaction. The implications of such developments in the field of
quantum sensing remain now to be explored.
This PhD project aims to bring mechanical scanning probes into the experimental quantum
domain using optomechanics. Quantum theory postulates indeed that energy exchanges
between physical systems take place with a certain granularity, in quantities that are multiples
of an energy quantum. This quantum regime of interactions has never been illustrated by local
mechanical measurements, such as those made with an atomic force microscope (AFM).
Detecting the exchange of a single quantum of energy between a physical system and
mechanical force probe represents the ultimate level of sensitivity allowed by microscopic
laws, and is therefore a considerable scientific and technological stake for sensing
applications of optomechanics.
Contact
Adrien Borne
05/11/2024
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Thèse :
Rémunération :
22
Quantum states of motion of a mechanical resonator
Domaines
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Expérimental et théorique Description
Similarly to single atoms, the motion of massive, mesoscopic-scale mechanical resonators can
behave quantum mechanically when cooled down to ultra-low temperatures. The study of
quantum states of motion of such systems has both fundamental and practical interests: for
testing quantum mechanics in systems beyond the few-particle ensembles, its interplay with
gravitation; also in force sensing, or as a light-matter interface for the development of
quantum communication networks, in particular for storing and transducing the quantum
information.
In this context, this internship/PhD project aims at generating targeted quantum states of the
motion of an optomechanical resonator such as the microdisk pictured above and developed in
our group. Fock and coherent superposition states will be considered, chosen arbitrarily in
the low phonon number regime. This mechanical quantum information can be encoded in the
device through its interaction with light, and then characterized through optical
tomographic reconstruction. This work will also consider increasing the dimensionality by
including several optomechanical resonators, thereby involving entanglement of massive
objects.
Contact
Adrien Borne
05/11/2024
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Thèse :
Rémunération :
23
Optical lattice clock with Laguerre-Gauß profiles
Domaines
Quantum optics/Atomic physics/Laser
Metrology
Type de stage
Expérimental Description
Optical lattice clocks are now the best frequency standards, with uncertainties in the 10^-18 range, and are well positioned to replace the Cs atom for the next definition of the SI second. The aim of this internship is to perform the clock spectroscopy of ultra-cold strontium atoms trapped in an optical lattice with Laguerre-Gauß shaped profiles, in order to improve our understanding of the main systematic effects limiting the accuracy of the clock.
Contact
Jérôme Lodewyck
Laboratoire : SYRTE - UMR 8630
Equipe : Métrologie des fréquences optiques (FOP)
Site Web de l'équipe
Equipe : Métrologie des fréquences optiques (FOP)
Site Web de l'équipe
05/11/2024
/
Thèse :
Rémunération :
24
Scanning Tunnelling Microscopy and Spectroscopy (STM/STS) of two-dimensional topological and correlated van der Waals heterostructures
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Two-dimensional van der Waals heterostructures formed by graphene and/or transition metal dichalcogenides (TMDCs), have become a captivating platform for exploring the interplay between strong electronic correlations and non-trivial band topology[1]. The recent discovery of fractional quantum anomalous Hall insulators at zero magnetic field, in a moiré heterostructure of rhombohedral pentalayer graphene aligned with hBN[2], is of intense interest as its non-Abelian anyonic excitations could be used for decoherence-free quantum computation.
The project aims to study, by STM in ultra-high vacuum and low temperature (4.2 K), bilayer graphene (AB-G) and rhombohedral graphene (ABCA-G) heterostructures aligned with hexagonal boron nitride (hBN) and in proximity to TMDCs like WSe2. The research will focus on understanding the emergence of topological band structures in these materials.
In addition to STM, the student will have the possibility to participate to the microfabrication of the heterostructures supervised by R. Ribeiro in the PHYNANO group, learn to work in a clear room environment and perform transport measurements.
Contact
Hervé Aubin
05/11/2024
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Thèse :
Rémunération :
25
Quantum magnetism of spin chains studied by Electron-Spin-Resonance using spin-polarized Scanning Tunneling
Domaines
Condensed matter
Nouveaux états électroniques de la matière corrélée
Quantum Machines
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Recent advances in Electron Spin Resonance – Scanning Tunnelling Microscopy (ESR-STM) are now making possible the study of electron spin resonance on single adatoms or molecules. At C2N, we developed an ESR-STM instrument that will be used for continuous-wave and pulsed ESR-STM. Pulsed ESR-STM allows measurements of Rabi oscillations, Cf. Fig., to characterize quantum coherence at atomic scale[1,2].
The project of the master/PhD is to fabricate spin-chains from magnetic molecules and to characterize the quantum coherence properties of the chain with atomic resolution.
Such studies are of fundamental interest for the field of quantum magnetism with topologically non-trivial excitations, such as Haldane spin-chains, expected to have long quantum coherence time.
Contact
Hervé Aubin
05/11/2024
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Thèse :
Rémunération :
26
Interactions atomes-photons avec un guide d’onde à modes lents à dispersion contrôlée : propriétés collectives et applications à la waveguide QED
Domaines
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
See pdf attached :)
Contact
Nikos Fayard
05/11/2024
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Thèse :
Rémunération :
27
Controlling Fractional Quantum Hall Systems through Cavity Quantum Electrodynamics
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Théorique, numérique Description
We have recently demonstrated the significant influence that interactions between cavity quantum electromagnetic fields and topological quantum materials—such as quantum Hall systems and 2D moiré materials—can have on their quantum transport and topological properties. In this theoretical internship, the Master's student will gain expertise in and apply advanced theoretical techniques from quantum many-body physics and cavity Quantum Electrodynamics (QED). This internship, which may lead to a subsequent PhD, will focus on exploring non-trivial topological phases in fractional quantum Hall systems and fractional Chern insulators. These are crucial strongly correlated quantum materials for both fundamental physics and applications in topological quantum information.
Contact
Cristiano Ciuti
05/11/2024
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Thèse :
Rémunération :
28
Developing charge-tunable coupled quantum dot devices for quantum computation
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Expérimental Description
In this internship we will fabricate coupled quantum dots, where the two dots are close enough that carriers can tunnel coherently between them. We will do this using molecular beam epitaxy, a thin-film growth technique, which allows precise control of layer thicknesses and composition. These dots will be embedded in diode structures allowing a field to applied across the dots, bringing their energy levels into resonance to create delocalised electronic states. The student will have the opportunity to participate in all the stages of development of a new
quantum device: from device design, thin film growth and device fabrication to the low
temperature photoluminescence measurements of quantum confinement effects.
Contact
Paola Atkinson
04/11/2024
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Thèse :
Rémunération :
29
Non-Reciprocal Quantum Matter
Domaines
Condensed matter
Nonequilibrium statistical physics
Quantum information theory and quantum technologies
Quantum optics
Non-equilibrium Statistical Physics
Type de stage
Théorique, numérique Description
In classical or quantum systems in thermal equilibrium the interactions between degrees of freedom are fundamentally symmetric or reciprocal, a statement dictated by Newton’s third law and that in the quantum domain comes hand in hand with unitarity. Far from equilibrium however non-reciprocal interactions happen to be more the rule than the exception. Examples include optics, active matter, ecology and recently quantum systems. Non-reciprocity emerges naturally within non-Hermitian quantum mechanics, such as in the celebrated Hatano-Nelson model of particles hopping across a lattice with hopping different rates along opposite directions, and lead to a plethora of exotic topological and non equilibrium phenomena. The goal of this project is to explore the consequences of non-reciprocity on the dynamics of quantum many-body systems. Examples include the study of transport entanglement and phase transitions in presence of non-reciprocal couplings, in paradigmatic models of quantum many-body systems such as quantum spin chains or strongly correlated quantum impurity models.
Contact
Marco Schiro
04/11/2024
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Thèse :
Rémunération :
30
Looking for potential variations of the proton-to-electron mass ratio and other tests of fundamental physics via precision measurements with molecules
Domaines
Quantum optics/Atomic physics/Laser
Relativity/Astrophysics/Cosmology
Quantum information theory and quantum technologies
Non-linear optics
Metrology
Type de stage
Expérimental Description
The master student will participate in cutting-edge experiments aimed at ultra-precise measurements of rovibrational molecular transitions and dedicated to measuring/constraining the potential time variation of the proton-to-electron mass ratio (µ), a fundamental constant of the standard model (SM). Such variations, if detected, would be a signature of physics beyond the SM, providing insights into the nature of dark matter and dark energy. The idea here is to compare molecular spectra of cosmic objects with corresponding laboratory data. The experimental setup is based on quantum cascade lasers (QCLs) locked to optical frequency combs, with traceability to primary frequency standards, a breakthrough technology at the forefront of frequenccy metrology developed at Laboratoire de Physique des Lasers (LPL), allowing unprecedented spectroscopic precision in the mid-infrared range.
Contact
Benoît Darquié
Laboratoire : LPL - UMR7538
Equipe : Métrologie, Molécules et Tests Fondamentaux (MMTF)
Site Web de l'équipe
Equipe : Métrologie, Molécules et Tests Fondamentaux (MMTF)
Site Web de l'équipe
02/11/2024
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Thèse :
Rémunération :
31
ULTRACOLD ATOM GRAVIMETER
Domaines
Quantum optics/Atomic physics/Laser
Metrology
Type de stage
Expérimental Description
We have developed a state-of-the-art cold atom gravimeter with free-falling 87Rb atoms, which experience a sequence of Raman pulses driven by counter-propagating vertical lasers. The atom interferometer phase shift is proportional to g, that we measure with better performances than conventional state of the art gravimeters. Limits have been identified and several improvements will be made to reach the 10-10 range both in term of accuracy and stability.
We will implement a crossed dipole trap with a 50W laser at 1.1μm to freeze atom source to nK range to tackle the wavefront aberration bias. A new rotatable retro-reflexion mirror for the Raman lasers will be installed. This will improve our control of the laser alignment and allow to compensate Coriolis acceleration. In order to improve our control on the initial position of the atoms, new MOT collimators will be installed, as well as an innovative fiber splitter system for the control of the powers in each MOT beam.
We will optimize the evaporation sequence, by increasing the capture volume of the trap using modulation techniques. Yet, a drawback when using dense samples of ultracold atoms, eventually Bose-Einstein condensed, instead of a more dilute laser cooled source, arises from the effect of interatomic interactions, which we will also investigate. The obtained uncertainty budget and sensitivity performances will finally be tested during comparisons with absolute and superconducting gravimeters.
Contact
Sébastien Merlet
01/11/2024
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Thèse :
Rémunération :
32
RECONFIGURABLE PLASMONIC MATRIX ANTENNAS FOR THERMAL EMISSION CONTROL
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Metrology
Type de stage
Expérimental Description
The aim of this project is to create nanostructured infrared plasmonic antennas based on the repetition of a single sub-wavelength metal pattern (sub-lambda) forming the basic building block of an NxN matrix structure. We will design reconfigurable infrared sources by addressing a subset of the sub-lambda patterns making up the matrix antenna with visible laser heating forming specific patterns, in particular to control the polarization and spectral position of resonances with a view to creating smart reconfigurable infrared surfaces. We will describe the coupling between sub-lambda patterns using simulations based on the quasi-normal mode method.
The use of a spatial light modulator will enable us to modify the spatial configuration of this laser heating on the antenna array. The result will be a reconfigurable light converter from visible to infrared.
The experimental methods will combine infrared spatial modulation spectroscopy [Li2018,Abou_Hamdan2021], thermal radiation scanning tunneling microscopy [DeWilde2006] and TRSTM spectroscopy which has revealed non-planckian effects [Babuty2013].
Contact
Yannick DE WILDE
Laboratoire : Institut Langevin - Ondes et Images - UMR7587
Equipe : Materials, Resonances, Interfaces
Site Web de l'équipe
Equipe : Materials, Resonances, Interfaces
Site Web de l'équipe
31/10/2024
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Thèse :
Rémunération :
33
MANY-BODY NEAR-FIELD RADIATIVE HEAT TRANSFER: TOWARDS A TRANSISTOR FOR THERMAL PHOTONS, BEYOND PLANCK'S LAW
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Metrology
Type de stage
Expérimental Description
Two solid bodies at different temperatures separated by vacuum exchange heat in the form of thermal photons. This exchange of energy is limited in the far field by Stefan-Boltzmann’s law which is a direct consequence of Planck's law. In the near field (when the separation distance is smaller than the thermal wavelength) the flux can overcome this limit by several orders of magnitude due to tunneling of photons making this transfer prominent at nanoscale. Until recently, only the radiative exchange between two objects has been considered in this non-planckian near-field regime.
In this project, we propose to develop the very first setup to experimentally investigate the near-field radiative heat exchanges by thermal photons in many-body systems. We will specifically address the case of micrometer-size objects for which the appropriate multipolar theoretical formalism will be developed by our collaborators (P. Ben-Abdallah and R. Messina, Labo. Charles Fabry – IOGS), to go beyond the dipole approximation suited for objects much smaller than the thermal radiation wavelength.
To this end, we will:
• Install additional probes in the experimental set-up developed by the previous PhD student (from Master ICFP).
• Measure the near-field heat exchanges in simple many-body systems by means of multiple interacting SThM probes. In parallel, a general formalism and/or numerical simulations will be developed to study the mutual radiative heat exchanges in many-body systems.
Contact
Yannick DE WILDE
Laboratoire : Institut Langevin - Ondes et Images - UMR7587
Equipe : Materials, Resonances, Interfaces
Site Web de l'équipe
Equipe : Materials, Resonances, Interfaces
Site Web de l'équipe
31/10/2024
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Thèse :
Rémunération :
34
Effect of controlled losses on a one-dimensional bose gas
Domaines
Condensed matter
Low dimension physics
Non-equilibrium Statistical Physics
Quantum gases
Type de stage
Expérimental Description
In cold atom experiments, it is possible to realize one-dimensional (1D) gases by freezing out the transverse degrees of freedom. The effective 1D interactions between atoms are well modeled by contact interactions. We thus realize the Lieb-Liniger model which describes 1D Bosons with contact interactions. This paradigmatic model of N-body physics belongs to the class of integrable models. As a consequence the system supports quasi-particles of infinite lifetime, labeled by their velocity called rapidity. Owing to their infinite lifetime, the distribution of rapidities is constant over time. Thus the system, if prepared with a non-thermal rapidity distribution, will never relax to a thermal state. This is in contrast to ergodic systems which relaxe, with respect to local observables, towards a thermal state. Preparing an integrable system in a non-thermal state and characterizing the latter will be a major advance.
We aim to achieve non-thermal states of 1D Bose gas in the LCF atom chip experiment by implementing losses, since, accroding to theoretical studies, losses should produce non-thermal states.
The characterization of the system will be done using the measurement protocol of the rapidity distribution recently implemented on our experiment. During this internship, the student will will install the device which allows losses to be achieved by microwave coupling to a non-trapped state and he/she will participate to the implementation on the atoms.
Contact
Isabelle Bouchoule
31/10/2024
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Thèse :
Rémunération :
35
Theory of Josephson junction lasers in superconducting circuit QED
Domaines
Condensed matter
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Non-equilibrium Statistical Physics
Type de stage
Théorique, numérique Description
Superconducting circuits are a promising platform for quantum engineering. They have many applications ranging from amplifiers and detectors to quantum computers and quantum metrological standards. Superconducting circuits are also used in fundamental science, as they can simulate paradigmatic models of quantum many-body physics and quantum electrodynamics. One example of fundamental effects is lasing that has been observed for a small nonlinear driven quantum system (a voltage-biased Josephson junction) coupled to a microwave photonic bath (a multi-mode superconducting resonator). Another experiment showed that a similar system could also end up in a thermal rather than coherent state.
The task now is to develop a theory which could describe the transition between coherent and thermal states of the resonator. On the semiclassical level, we have to describe a transition between regular and chaotic motion of a complex dynamical system. On the quantum level, we face the problem of thermalization or its absence in a driven-dissipative quantum many-body system. The first step, which is the subject of this internship, will be to construct a classical coherent lasing solution for a lambda/4 resonator. This work will involve analytical
and numerical calculations.
Contact
Denis Basko
31/10/2024
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Thèse :
Rémunération :
36
Quantum Optics with Exciton-Polariton Neural Networks
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Non-linear optics
Quantum gases
Type de stage
Expérimental Description
To fully characterize a quantum state of light, repeated measurements involving a phase reference, eg. homodyne detection, are required. The Quantum Fluids of Light team has recently begun an ambitious project to realize a quantum reservoir processor capable of fully characterizing quantum states of light from intensity measurements only, eliminating the need for a phase reference.
To achieve this goal, we have begun implementing a quantum neural network of (exciton-)polaritons - strongly interacting quasiparticles which are part-light, part-matter. Polaritons are ideal for a reservoir computing architecture, as not only do they exhibit rich dynamics governed by the Gross-Pitaevski equation (a phase transition, bistability, and famously, superfluidity), they are themselves quantum objects.
The intern will work in close collaboration with a post-doctoral researcher to study the response of the polariton network to excitation by different optical states, while simultaneously beginning to implement a squeezed source resonant with the polaritons, with the prospective to join the team as a PhD student in Fall of 2025. As the work will take place within the context of a European project, the student will have the opportunity to work in a fast-moving, exciting, and international collaboration, whose stated goal is to realize a disruptive quantum technology.
Contact
Alberto Bramati
30/10/2024
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Thèse :
Rémunération :
37
Rare-earth doped oxide thin films for on-chip optical quantum technologies
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
We search for a motivated master student to work on rare earth ion doped thin films for quantum technologies at the Crystals and Quantum State Dynamics Team. We have developed a hybrid thin film fabrication approach combining MBE and CVD deposition techniques to obtain quantum-grade epitaxial rare-earth oxide thin films on silicon . This internship will have two main objectives: (i) the optimisation of the thin-film deposition conditions towards the reproducible obtention of smooth epitaxial Y2O3 thin films doped with REI. (ii) the fabrication of Y2O3 membranes by both dry and wet chemical etching techniques. The deposited thin films, and membranes quality and eligibility for quantum technology applications
will be assessed by the candidate using different morphological and optical characterisations. We search for candidates aiming at continuing this research in the framework of a PhD project.
Contact
Diana SERRANO
30/10/2024
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Thèse :
Rémunération :
38
Multiscale mid-infrared femtosecond spectroscopy in proteins
Domaines
Quantum optics/Atomic physics/Laser
Biophysics
Physics of living systems
Non-linear optics
Type de stage
Expérimental Description
The purpose of the proposed project is to apply multiscale pump-probe spectroscopy to monitor the motion of a carbon-monoxide ligand inside hemoglobin over the entire biologically-relevant timescale, in order to understand the key role of the protein structure in its functions. The project will benefit from unique methods we recently developed, including high-resolution mid-infrared femtosecond spectroscopy and the ability to control the pump-probe delay up to milliseconds.
Contact
Manuel Joffre
30/10/2024
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Thèse :
Rémunération :
39
Excitonic and spin properties of halide perovskites
Domaines
Condensed matter
Type de stage
Expérimental Description
In recent years, halide perovskites have demonstrated exceptional optoelectronic properties. This new class of semiconductor materials has proved an extraordinary potential for the production of low-cost solar cells and light-emitting devices. Perovskite solar cells have made lightning progress, and now boast efficiencies over 26%, on par with the best silicon-based solar cells. This success leads to significant research effort to understand the physical origins of their performance. Halide perovskites are also promising for spintronic applications. They present a strong spin-orbit coupling, a relatively long spin relaxation times, and optical accessibly for spin generation and defection. Room temperature coherent optical manipulation of spins has been recently achieved.High spin injection efficiency has been demonstrated at room temperature at a chiral perovskite/III-V interface.
The objective of the Master thesis, which could be followed by a PhD thesis, is to explore the exciton and spin properties of halide perovskites.
Contact
Damien Garrot
29/10/2024
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Thèse :
Rémunération :
40
Noise modeling and applications of a small-scale superconducting processor
Domaines
Quantum Machines
Quantum information theory and quantum technologies
Type de stage
Théorique, numérique Activité en entreprise
Description
Superconducting qubits are among the most advanced qubits. Within its partnership with Finnish startup IQM, Eviden has access to a superconducting processor through its Qaptiva platform. The goal of this internship is to characterize the noise model of this processor (using e.g tomography methods) and use this characterization to improve experimental runs in several application domains using e.g error mitigation techniques.
Contact
Thomas Ayral
29/10/2024
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Thèse :
Rémunération :
41
Realistic emulation of a trapped-ion quantum chip with tensor networks
Domaines
Quantum information theory and quantum technologies
Type de stage
Théorique, numérique Activité en entreprise
Description
Trapped ions is one of the most important technologies explored for building a quantum computer. Their technical specificities give them particular error and noise sources, which must be taken into account when emulating their operation on classical hardware.
In this internship, we aim at emulating a trapped ions experiment in collaboration with an experimental team based in Innsbruck (Austria). A precise noise model will be built. The emulation will use tensor network techniques that may have to be adapted to trapped ions, implying code development of cutting edge tensor network algorithms, such as the Time-Dependent Variational Principle (TDVP) method, potentially as a part of Qaptiva.
Contact
Thomas Ayral
29/10/2024
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Thèse :
Rémunération :
42
High-precision numerical assessment of quantum error correction performance
Domaines
Quantum information theory and quantum technologies
Type de stage
Théorique, numérique Activité en entreprise
Description
Quantum error correction (QEC) is the holy grail of quantum computing because it allows to counter the deleterious influence of decoherence. Yet, it comes at a price: hardware noise must be under a given threshold for QEC to deliver improved performance. The most widespread way of estimating the QEC threshold involves making several assumptions as to the hardware noise and the decoding process. These assumptions allow for an efficient numerical simulation of the QEC process, but yield only approximate thresholds.
The goal of this internship is to compute more realistic QEC thresholds by removing the simplifying assumptions. This leads to much more complex numerical simulations, yet also much more useful predictions that could be used to tailor QEC codes to a given hardware. The internship will greatly benefit from the HPC Qaptiva emulators.
Reference: http://arxiv.org/abs/1711.04736
Contact
Thomas Ayral
29/10/2024
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Thèse :
Rémunération :
43
From qubit noise to dissipative baths of electrons: how to take advantage of imperfect hardware
Domaines
Condensed matter
Nouveaux états électroniques de la matière corrélée
Nonequilibrium statistical physics
Quantum information theory and quantum technologies
Non-equilibrium Statistical Physics
Type de stage
Théorique, numérique Activité en entreprise
Description
Noise in quantum computers is usually considered negatively as it destroys quantum information exponentially fast and therefore poses huge constraints on the duration or depth of quantum algorithm. However, noise is also a source of dissipation, which is a fundamental aspect in condensed matter physics: for instance, dissipation is often instrumental in driving physical systems to equilibrium or at least to a steady state.
It turns out that noise can possibly be used to one’s advantage by using advanced algorithms. In this internship, we will explore how to take advantage of qubit noise to build quantum algorithms for the study of systems of interacting fermions coupled to dissipative baths.
Contact
Thomas Ayral
29/10/2024
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Thèse :
Rémunération :
44
Excitonic whispering gallery mode laser in high pumping regime
Domaines
Quantum optics/Atomic physics/Laser
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
In nanophotonics and quantum technologies, photon sources are a ressource which can be integrated into a chip. Cylindrical dielectric microdisks make excellent resonators in which optical gallery modes can propagate at the air/dielectric interface.
Using optical lithography, we have fabricated gallery-mode resonators on which we have deposited fluorescent nano-emitters, colloidal quantum dots. These are CdS/CdSe/CdS semiconductors in a spherical core/shell/shell configuration. Of nanometric dimensions, their fluorescence wavelength depends on their size. They can emit single photons, are resistant to photobleaching and are bright under strong excitation. We have deposited these quantum dots in high concentration on microdisks, and excited them with a green laser. The excitons thus created enabled us to achieve a significant gain. We were therefore able to create gallery modes excitonic microlasers. [1].
The aim of this internship will be to study these gallery-mode lasers, and to understand their characteristics as a function of their size, of the excitation when it is close to the laser threshold or more higher...
[1] C. Kersuzan et al, ACS Photonics, 11(4), 1715-1723 (2024)
Contact
Agnes MAITRE
29/10/2024
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Thèse :
Rémunération :
45
Quantum communications at 10 µm wavelength
Domaines
Condensed matter
Low dimension physics
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Quantum communication exploits the fundamental laws of quantum physics to protect data with applications in bank transactions, financial trading and sensitive communications. The objective of this project is the realization of systems that assemble unipolar quantum optoelectronic devices (metamaterial photodetectors and phase modulators) with local oscillators to demonstrate quantum communications in the mid-infrared. This ambitious goal will be achieved by exploiting low-noise and high-sensitivity multiheterodyne detection systems.
Contact
Baptiste Chomet
29/10/2024
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Thèse :
Rémunération :
46
Generating nonclassical states of light using waveguide quantum electrodynamics
Domaines
Quantum optics/Atomic physics/Laser
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Quantum information theory and quantum technologies
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
This internship offer is for a Master’s student interested in quantum optics, specifically in generating nonclassical states of light using waveguide quantum electrodynamics. The project, based at LKB, Jussieu campus, involves theoretical modeling and simulation of photon interactions with quantum emitters to create quantum states and understand their formation. The intern will perform theoretical calculations, develop computational models, and collaborate with the research team. Applicants should have knowledge in quantum mechanics or optics, and experience with Python is advantageous.
Contact
Hanna Le Jeannic
29/10/2024
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Thèse :
Rémunération :
47
Nano-laser arrays for quantum sensing in the mid infrared (wavelength ~ 10µm)
Domaines
Condensed matter
Low dimension physics
Quantum Machines
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
The objective of the PhD research project is to realise an array of quantum cascade (QC) nano-lasers by conceiving a photonic structure that merges concepts from microwave and optics. Indeed, concepts from the microwave range based on antenna theory could be implemented at much higher frequencies to spark new hybrid devices merging optics and electronics, dielectric and metals. Metallic antennae will be used to realise microcavities to enhance light-matter interaction and produce light emission. In particular patch-antennae will be adapted to produce an array of QC lasers that contribute to produce a coherent collective mode with substantially new performances in terms of wavelength engineering, spatial beam properties and low energy consumption. The properties of this photonic structure will be a mean to explore the quantum properties of the emitted light.
Contact
Carlo Sirtori
29/10/2024
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Thèse :
Rémunération :
48
Exploiting many-body properties for advanced quantum devices
Domaines
Condensed matter
Low dimension physics
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
The optical properties of highly doped semiconductor quantum wells are a paradigmatic manifestation of P. Anderson’s “More is different”. Indeed, for high electronic densities, there are no more optical transitions between electronic states and the absorption spectrum of the system shows a unique resonance associated with a collective mode of the system: the quantum plasmon.
In this project, we plan to exploit the superradiant properties of quantum plasmons to create efficient cold sources, operating as mid-infrared light-emitting diodes.
Contact
Angela Vasanelli
28/10/2024
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Thèse :
Rémunération :
49
Phase modulators for quantum optics in the mid-infrared
Domaines
Condensed matter
Low dimension physics
Quantum optics
Type de stage
Expérimental Description
The aim of this project is the realization of phase modulators in the mid-infrared. Such devices will be implemented in a waveguide geometry, and they will be exploited to realize a Mach-Zehnder interferometer. Combined with a sensitive mid-infrared detector, such interferometer would be the first building block for a fully integrated heterodyne detection platform, opening the path towards extending the realm of quantum optics towards the mid-infrared domain.
Contact
Angela Vasanelli
28/10/2024
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Thèse :
Rémunération :
50
Causal decompositions of unitary processes
Domaines
Relativity/Astrophysics/Cosmology
Quantum information theory and quantum technologies
Type de stage
Théorique, numérique Description
The conjecture of causal decompositions proposes that there is an equivalence between two fundamental structures of quantum theory: causal structure and compositional structure. It would provide a dramatic connection between an empirical, operationally accessible notion (causal structure) and a powerful mathematical structure (compositional structure). This conjecture has recently been proven in the case of 1D Quantum Cellular Automata (QCAs), (which can be seen as representing lightcone-abiding dynamics in a discretised (1+1)D Minkowski spacetime), using novel and powerful mathematical techniques that employ C* algebras. The proof is however limited to a finite number of spatial sites, because the techniques have only been developed for finite-dimensional C* algebras.
The project is for the students to generalise this proof to the infinite case, by investigating the extension of these techniques to the case of C* algebras of infinite dimension. This project is expected to require a significant deal of mathematics and abstraction, but the tools to be developed hold deep physical significance and promise to find application in other fields. The internship could continue into a PhD.
Contact
Augustin Vanrietvelde
28/10/2024
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Thèse :
Rémunération :
51
Towards photoelectric detection of single microwave photons using a super-inductance circuit
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental Description
Developing efficient and fast single microwave photon detectors holds immense promise in advancing quantum computing, communication and sensing. Historically, the technology used by optical photon detection is based on semiconductor materials whose gap appropriately matches the frequency domain of interest. Transferring this technology to microwave photons fails due to the natural mismatch between semiconducting gap and microwave frequency photons.
We have recently overcome this problem by realizing a quasi-ideal microwave photon to electron converter in which a superconducting tunnel junction acts as a voltage tuneable quantum absorber through the photon-assisted tunneling of quasiparticles. The achieved quantum efficiency approaches unity.
We are now seeking for an enthusiastic student to work on the development of detection techniques to measure the single charge associated to the absorption of a single microwave photon. The goal will be to develop charge detection using superconducting circuits made out of granular aluminum, a disordered superconductor, realized in a nanofabrication clean room by electron beam lithography and metal evaporation. Measurements will then be carried in a new dilution refrigerator with base temperature of 20 mK and high precision electronics. The student will also get involved into numerical simulations of the quantum master equation governing the dynamics of the system.
Contact
Jérôme ESTEVE
28/10/2024
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Thèse :
Rémunération :
52
Fluctuations of supercurrent carried by topological insulator edge states
Domaines
Condensed matter
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Discovery of topological matter has triggered an intense research work motivated by the emergence of promising features among which the existence of helical ballistic edge states. For 2D systems or 3D high order topological insulators, they form one dimensional conducting channels on the edges with two time-reversed spin-momentum-locked states which do not backscatter. Using our newly developped ultrasensitive GMR-based (Giant Magnetoresistance) magnetic field sensor, we plan to detect the supercurrent carried by the helical edge states as well as its fluctuations at equilibrium, which are predicted to contain clear signature of the relaxation mechanism and topological protection.
Contact
Meydi Ferrier
28/10/2024
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Thèse :
Rémunération :
53
Limits of Quantum Correlations
Domaines
Quantum information theory and quantum technologies
Type de stage
Théorique, numérique Description
The probabilistic nature of quantum theory has deep consequences both on our understanding of the theory and on the potential applications that can be built with it. In fact, quantum statistics play a key role throughout quantum information theory. Yet, quantum correlations remain poorly understood. While some methods have been proposed to approach these statistics, they are generally either partial or implicit.
The aim of this internship is to identify some explicit regions of the quantum boundary analytically. By providing new ways of testing whether some statistics admit a quantum explanation or not, this work will help to characterize both the power and the limitations of quantum predictions. It may also lead to applications in self-testing and the certification of quantum technology devices, as well as in the study of quantum networks.
Contact
Jean-Daniel Bancal
28/10/2024
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Thèse :
Rémunération :
54
Monitored Quantum Many-Body Systems
Domaines
Condensed matter
Statistical physics
Nonequilibrium statistical physics
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Théorique, numérique Description
Unitarity is a fundamental property of quantum mechanics which underlies the dynamics of closed quantum many-body systems, the concept of thermalisation and the emergence of statistical mechanics. A different paradigm for quantum dynamics arises in presence of an external environment, which can represent for example dissipation due to a bath or an external monitoring apparatus[1,2]. Other sources of non-unitarity can arise for example in presence of non-Hermiticity due to post-selection of measurement outcomes [3].
The goal of this project is to explore the consequences of non-unitarity on the dynamics of quantum many-body systems, in particular for what concerns the dynamics of quantum information. Examples include: the study of entanglement dynamics in presence of quantum measurements or continuous monitoring, the use of measurements and active feedback to steer and prepare quantum many-body states.
Contact
Marco Schiro
27/10/2024
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Thèse :
Rémunération :
55
Disorder and charge dynamics in nitride semiconductor heterostructures: new experimental tools for more efficient devices
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
We propose an internship, and subsequent thesis, aimed at studying the opto-electronic consequences of nanoscale disorder in nitride semiconductor heterostructures used in lighting applications. To do so, the candidate may use novel experiment tools developed at Ecole polytechnique, including scanning tunnelling luminescence microscopy which combines the spatial resolution of STM with the spectral resolution of optical spectroscopy, low energy photo-emission and high resolution photoluminescence and photoluminescence excitation spectroscopy. These tools are unique in that they are used to study fundamental physical processes affecting electron dynamics in operational devices, including commercial light-emitting diodes. As such, our goal is to provide physical insights that will help to design the high efficiency light emitters of tomorrow.
Contact
Alistair Rowe
26/10/2024
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Thèse :
Rémunération :
56
Shining light on superconducting 2D transition metal dichalcogenides
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Transition metal dichalcogenides (TMDs) have recently attracted significant interest because they allow the exploration of novel quantum phenomena down to the 2D limit. Of particular interest for the present project are metallic TMD like NbSe2 which displays various quantum phases like Superconductivity (SC) and charge density wave (CDW) states [Xi16]. The possibility of fabricating these 2D crystals into vertical “van der Waals” (VdW) heterostructures make them ideal candidate for the integration into cavities to enhance light-matter interaction and achieve cavity control of quantum phases. In addition, the formation of Moiré patterns due to the lattice mismatch and crystalline misalignment between vertically stacked layers is another unique aspect of the VdW layered structures, offering opportunities for quantum engineering of material properties [Cao18].
During the internship, the student will participate in the first steps of this ambitious project. He/she will study TMD-based VdW heterostructures displaying SC properties using exfoliation techniques. Going beyond traditional transport measurements, an originality of the project will be the use of low temperataure spectroscopic techniques with micron-size spatial resolution like Raman scattering to probe the SC state [Grasset2018,Grasset2019]. In the longer term these optical techniques will be implemented in out-of-equilibrium pump-probe schemes and in equilibrium on cavity-integrated samples.
Contact
Yann Gallais
26/10/2024
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Thèse :
Rémunération :
57
Optical microcombs exploiting both quadratic and cubicnonlinearities
Domaines
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
High-contrast microrings combine high Q factors and small cross section, allowing for strong nonlinear light-matter interaction at low optical power and group-velocity-dispersion management. Such cavities are used in an increasing set of photonic applications including frequency comb (OFC) generation.
Over the last years, Kerr OFCs, generated in high-Q microresonators with cubic nonlinearities, have raised significant interest. They offer broadband spectra with uniform line powers, free spectral ranges up to 100's GHz, and chip-scale integration. Kerr “microcombs” thus open the potential to disrupt a series of highly relevant applications, ranging from massively parallel wavelength-division multiplexing in optical communications to high-resolution spectroscopy. Despite this potential, full deployment of Kerr combs is still hindered by stability and uniformity issues, plus limited spectral spanning. In addition, efficient schemes for controlling the carrier-envelope offset frequency of Kerr combs are still lacking, thereby impeding the application of Kerr combs in high-precision optical metrology and optical frequency standards.
In this internship, by combining Kerr-type cubic with quadratic optical nonlinearities, we will explore and implement novel approaches for OFC generation in photonic integrated circuits, which enable a richer nonlinear dynamics and stabilized carrier-envelope offset frequency.
Contact
Giuseppe Leo
26/10/2024
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Thèse :
Rémunération :
58
Toward 2D electron gases with strong spin-orbit coupling in crystalline metal- semiconductor heterostructures
Domaines
Condensed matter
Type de stage
Expérimental Description
The aim of this intership project and the following PhD thesis is to develop a strategy to preserve the strong Rashba effect in 2D heavy metallic layers on semiconducting surfaces and make use of these systems for spintronic applications. We will grow a dielectric capping material on the desired heavy metal in ultra-high vacuum environement, study the band structure of the heterostructures by ARPES and perform charge-spin conversion measurements by magneto-transport techniques.
Contact
Sergio Vlaic
25/10/2024
/
Thèse :
Rémunération :
59
Tuning the electronic and magnetic properties of 2D antimonene via doping with magnetic impurities
Domaines
Condensed matter
Type de stage
Expérimental Description
In this intership project we propose to study the electronic properties of antimonene, a 2D allotrope of antimony, grown on topological insulators, by angle resolved photoemission electron spectroscopy (ARPES). The antimonene layer will be doped with magnetic impurities to induce ferromagnetism. This intership project, and the follow up PhD thesis will be carried out in collaboration with the EPFL in Switzerland.
Contact
Sergio Vlaic
25/10/2024
/
Thèse :
Rémunération :
60
Novel electronic states and exotic phase transitions in correlated electron systems
Domaines
Condensed matter
Nouveaux états électroniques de la matière corrélée
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
According to the Bloch theory, considered the “Standard Model” for the quantum description of solids, metal or insulator are mutually exclusive states of matter. The very existence of a metal-to-insulator transition observed in some materials shakes the foundations of such a well-tested model! Such a transition is one of the most fundamental puzzles of modern Physics.
During this internship you will use angle-resolved photoemission spectroscopy (ARPES), a technique that directly images the electronic energies of a solid, to explore the changes in electronic structure and induced broken symmetries across the metal-to-insulator transition in V2O3. The experiments will be performed at several synchrotrons around Europe (France, Germany, Spain, Sweden, among others), and possibly Japan and China. You will also participate to the assembly and operation of a laboratory-based high-resolution ARPES system, aimed at exploring the MIT and other exotic states in correlated materials.
Contact
Andrés Felipe Santander-Syro
25/10/2024
/
Thèse :
Rémunération :
61
A laser-cooled trapped ion cloud for heavy particle detection
Domaines
Quantum optics/Atomic physics/Laser
Kinetic theory ; Diffusion ; Long-range interacting systems
Type de stage
Expérimental Description
One of the experimental set-up of the CIML group in Marseille aims at the experimental investigation of the energy exchange between charged particles, sending a projectile onto a target. There, the target is a cold and dense trapped ion cloud which can be considered as a very non-conventional plasma, a one-component plasma. The projectile is a very heavy molecular ion and the perturbation that it induces in crossing the cloud of trapped ions can be used for its non-destructive detection, to demonstrate a prototype for mass spectrometer detector without mass limitation.
Objectives : We propose to a master student to join this project to observe and study the energy exchange between charged heavy ions and laser cooled Ca+ trapped ion cloud. It implies to develop a protocol to control the size and temperature of the trapped ions, the trajectory of the projectile and a diagnostic of the energy transferred to the ion cloud. The internship relies on an operational experimental set-up, where the detection will take place. It can also rely on a molecular dynamics simulation code that can be used to test the detection efficiency regarding the projectile characteristics, the trap and the laser-cooling parameters.
The acquired skills concern charged particle trapping and guiding, atom-laser interaction and laser cooling, data acquisition and processing.
Contact
Caroline Champenois
25/10/2024
/
Thèse :
Rémunération :
62
Dynamics in ultracold plasmas
Domaines
Quantum optics/Atomic physics/Laser
Kinetic theory ; Diffusion ; Long-range interacting systems
Hydrodynamics/Turbulence/Fluid mechanics
Type de stage
Expérimental Description
Laser-cooled atomic samples provide highly controllable and versatile platforms to study complex phenomena. The ion trapping group in Marseilles studies laser-cooled calcium ions Ca+ trapped in linear radio-frequency (rf) traps. At temperatures lower than 1 K the trapped ions form a regular structure, called a Coulomb crystal, minimizing the total energy, as shown on the figure, which displays the fluorescence of the ions imaged by a camera. By playing with the lasers addressing the ions it is possible to shelve part of the cloud in a “dark state”, triggering a phase separation between bright and dark ions. By studying this process one can measure experimentally the self-diffusion coefficients in a one-component strongly correlated plasma, which is the topic of this internship offer.
Contact
Romain Dubessy
25/10/2024
/
Thèse :
Rémunération :
63
Superfluid Bose-Einstein condensates in bubble traps
Domaines
Quantum optics/Atomic physics/Laser
Quantum gases
Type de stage
Expérimental Description
The Bose-Einstein Condensate group at Laboratoire de Physique des Lasers studies superfluid dynamics of a degenerate bosonic gas confined at the surface of a bubble. We have evidenced in the bubble the formation of a vortex lattice when the gas is set into rotation, and observed the thermal melting of the lattice at large rotation frequency. In the internship, we propose to develop a new imaging system at a shorter wavelength to improve the imaging resolution, with the final goal of imaging the vortices directly inside the trapped gas.
Contact
Hélène Perrin
24/10/2024
/
Thèse :
Rémunération :
64
Towards a quantum interface between ionic qubits and entangled photons
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Non-linear optics
Metrology
Type de stage
Expérimental Description
Recent advances in quantum physics have given rise to cutting-edge fields such as quantum computing, quantum simulation, and quantum communication—driving the rapid development of quantum technologies.
Over the past few years, our research team has developed two experimental components using complementary quantum platforms: laser-cooled trapped ions and semiconductor sources of correlated photons.
This internship proposal is at the intersection of these two areas, with the goal of developing a hybrid quantum platform. The project focuses on addressing one of the key challenges in quantum communication networks: creating a seamless connection between static qubits (trapped ions) and flying qubits (single photons).
Contact
Valentin Cambier
24/10/2024
/
Thèse :
Rémunération :
65
Manipulating the Quantum Photon-Avalanche Process with Plasmonic Nano-Antennas
Domaines
Quantum optics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Phenomena such as earthquakes, landslides, forest fires, species extinctions, stock market crashes, and wars are all examples of self-organized criticality in nature, exhibiting avalanche-like behavior. In optics, a similar behavior is observed in the photon emission from certain rare-earth-doped nanoparticles, specifically those doped with thulium ions (Tm³⁺). This highly nonlinear phenomenon is known as the photon avalanche (PA).
The emission from these Avalanching Nanoparticles (ANPs) exhibits a nonlinear response to the excitation source (see Figure 1), making them promising probes for applications such as super-resolution biological imaging.
Building on our team's expertise in manipulating electric and magnetic light-matter interactions at the nanoscale, we propose to study the influence of plasmonic nano-antennas (see Figure 2) on the internal physical mechanisms of the photon avalanche.
As part of this fundamental research project, we will employ experimental techniques such as Scanning Near-field Optical Microscopy (SNOM), power-dependent measurements, and spectroscopic analysis to characterize the exotic behavior of ANPs.
Collaborating with the University of California, Berkeley, and Columbia University, this experimental project is at the forefront of a new field of research with high potential for significant scientific publications and technological applications.
Contact
Mathieu Mivelle
23/10/2024
/
Thèse :
Rémunération :
66
Spontaneous emission and quantum memory within a 1D atomic lattice
Domaines
Quantum optics/Atomic physics/Laser
Type de stage
Expérimental Description
Cold atoms are one promising platform to realize quantum memories with high efficiency. In our experiment we propose to use cold atoms trapped in a 1D lattice. The density modulation of the atoms creates a band gap and a Bragg reflection. Adding this to a standard quantum-memory protocol, we want to study how the increased density of state at the band edges can enhance the efficiency of the quantum memory, and how the Bragg reflection can be exploited to create two output ports for reading the stored light.
Contact
William Guerin
23/10/2024
/
Thèse :
Rémunération :
67
Study of strongly correlated fermions via stochastic evaluation of Feynman diagrams
Domaines
Condensed matter
Statistical physics
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Quantum gases
Type de stage
Théorique, numérique Description
Strongly correlated fermions are ubiquitous in various contexts: electrons in solids or molecules, nucleons in nuclei or neutron stars, quarks in QCD. Our understanding of such systems is limited by the difficulty to compute their properties in a reliable and unbiased way. For conventional quantum Monte Carlo methods, the computational time generically grows exponentially with the number of fermions (due to the “fermion sign problem”).
The situation is fundamentally different with connected Feynman diagrams, which can be computed directly for infinite volume. In contrast to usual diagrammatic calculations, we control the series-truncation error by going to high orders. To this end we develop Monte Carlo algorithms to efficiently sample diagrammatic series. In the cases where the series diverges, we study its the large-order asymptotic behavior, and use it to construct a resummation method capable of transforming the divergent series into a result that converges towards the exact physical value (in the limit of infinite truncation-order).
The internship/PhD project involves the development of diagrammatic Monte Carlo for the unitary Fermi gas model and/or impurity models (that accurately describe experiments on ultracold atomic gases conducted in several labs, e.g. LKB, MIT, Hamburg, Technion, Yale…).
Contact
Kris Van Houcke
Laboratoire : LPENS -
Equipe : Systèmes Classiques ou Quantiques en Interaction
Site Web de l'équipe
Equipe : Systèmes Classiques ou Quantiques en Interaction
Site Web de l'équipe
23/10/2024
/
Thèse :
Rémunération :
68
Manipulation of quantum gases with oscillating magnetic fields
Domaines
Quantum gases
Type de stage
Expérimental Description
The aim of this internship is to set up controllable radiofrequency and microwave sources to manipulate sodium quantum gases with oscillating magnetic fields. These new tools will extend the capacity of the experimental set-up for the study of one-dimensional Bose gases. After the internship, a funded PhD thesis may be proposed on this subject.
Contact
Aurélien Perrin
23/10/2024
/
Thèse :
Rémunération :
69
Exploring and optimizing the limits of nano-optomechanical coupling using quantum information-driven wavefront shaping
Domaines
Quantum optics/Atomic physics/Laser
Statistical physics
Quantum optics
Non-equilibrium Statistical Physics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Optomechanics investigates the reciprocal interactions between light and mechanical motion. The field has
recently completed major advance, including breaking into the quantum regime of the optomechanical
interaction, with the demonstration of the preparation and detection of quantum macroscopic motional
states. The premises of these milestones are to be found in the breakthrough of nano-optomechanical
systems in the early 2010, which have demonstrated the ability to harness large light-matter interactions at
the nanoscale for ultra-high sensitivity optomechanical purposes. So far, the sensitivity limits of these
systems has been treated along an approach similar to that developed for their macroscopic counterparts,
assuming both Gauss conditions and unitarity. These hypotheses, however, must be revised with nano-
optomechanical systems, which may presently be operated orders of magnitude away from their
sensitivity potential. Indeed, theoretical considerations for the Cramér-Rao bound, which defines the
ultimate limit of precision for parameter estimation, suggest that these systems are far from reaching their
optimal performance.
This internship is part of a project aiming at addressing the fundamental limits of nano-optomechanical
coupling using quantum information theory-driven wavefront shaping.
Contact
Loïc Rondin
21/10/2024
/
Thèse :
Rémunération :
70
Optomechanical response of rare earth ion doped hybrid systems
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Statistical physics
Quantum information theory and quantum technologies
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Quantum hybrid mechanical systems investigate the interactions between a quantum degree of freedom (a
qubit) and macroscopic mechanical motion. The main idea behind this concept is to create an interface
between the quantum and the classical domains, with the general perspective to experimentally extend
quantum foundational principles at the macroscopic scale. Since its emergence 20 years ago, quantum
hybrid optomechanical science has witnessed remarkable progress, in the microwave regime. Concurrently,
only a few approaches have successfully addressed hybrid mechanical coupling in the optical domain yet
with coupling strengths remaining far below the conditions for coherent quantum-mechanical interaction.
This is mainly because of the very short lifetime of the optical emitters used so far, imposing coupling rates
which presently appear out of reach. Our project tackles this very issue, by relying on the unique coherence
properties of the strain-induced optomechanical coupling in rare-earth ion doped crystals (see Fig. 1(a – b)).
With optical decoherence rates in the kHz range, we notably expect strain coupling to operate deep into
the strong coupling regime, provided large enough zero-point motion levels, which we will achieve by
engineering micro and nanomechanical structures.
Contact
Loïc Rondin
21/10/2024
/
Thèse :
Rémunération :
71
Ultra sensitive force sensing with levitated particle
Domaines
Quantum optics/Atomic physics/Laser
Statistical physics
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Nonequilibrium statistical physics
Non-equilibrium Statistical Physics
Type de stage
Expérimental Description
The development of increasingly sensitive force probes is essential
both from an application perspective (smartphones’ accelerometers,
gravimeters for monitoring Earth's climate [1], etc.) and from a
fundamental perspective (measuring forces beyond the Standard
Model [2]). To address these questions, it is necessary to have a
force sensors that is simple, robust, and highly sensitive. A promising
approach is the levitation of particles in a vacuum, which allows for
very high sensitivities due to the weak coupling between the particle
and its environment. Levitation relies on an optical trap, which uses
the forces associated with a laser beam to trap a nanoparticle at the
focal point of a objective (see figure). The particle then behaves like
a mechanical oscillator with a very high-quality factor, making it
highly sensitive to applying an external force.
In this context, this project aims to develop a force sensor based on
optical levitation and demonstrate its sensitivity, particularly in the
measurement of gravity. Depending on their interests, the student involved in the project may choose to focus
either on developing a prototype of an integrated and portable accelerometer or on pushing the force
measurement sensitivity to fundamental classical and quantum limits, in order to measure gravitational forces
beyond currently accessible sensitivities.
Contact
Loïc Rondin
21/10/2024
/
Thèse :
Rémunération :
72
Optical levitation of particles’ array: toward nanothermodynamics and quantum interactions
Domaines
Quantum optics/Atomic physics/Laser
Statistical physics
Nonequilibrium statistical physics
Non-equilibrium Statistical Physics
Type de stage
Expérimental Description
Optical levitation of particles in vacuum, offering excellent isolation from the environment, is a unique
platform for the study of fundamental interactions [1], thermodynamics of nano-systems [2], or
quantum physics at macro scales [3].
In that context, the opportunity to scale this system is particularly attractive to extend the capability
of the system, by providing a unique opportunity to observe quantum entanglement between massive
particles, to study anomalous energy flux at the nanoscale, or extend the sensibility of weakly
interacting particles (WIMPS) detectors.
The proposed internship aimed at developing a system to optically levitate multiple particles. This
system will be based on the optical tweezer setup we developed in the lab over the last few years.
The objective of the internship will then be to trap two particles and characterize their interactions,
both optical and electrostatics. These interactions will then be used to study energy exchange
between the coupled particles.
The developed setup will serve as a basis to study anomalous energy flux at the nanoscale and
quantum interaction between levitated massive particles.
The candidate should have a strong interest in experimental physics and know at least one of the
topics: nano-optics and photonics, atomic physics, stochastic physics. An interest in instrumentation
is a plus.
Contact
Loïc Rondin
21/10/2024
/
Thèse :
Rémunération :
73
399 nm moving molasses of cold Yb for a transportable optical lattice clock
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Non-linear optics
Metrology
Type de stage
Expérimental Description
Optical lattice clocks have reached such a resolution that they can now be controlled at the 18 digits level. This makes them able to detect a change of height of 1 cm, via a general relativity effect called gravitational time dilation. At SYRTE, Observatoire de Paris, we are building a transportable Ytterbium lattice clock, targeting ultrahigh stability, in order to participate to the cartography of the geopotential in the future. The M2 student will work on the construction of a new 399 nm laser source and the design of a moving optical molasses at this wavelength, in order to reach ultrafast trapping of ytterbium 171 atoms.
Contact
Rodolphe Le Targat
Laboratoire : SYRTE - UMR 8630
Equipe : Métrologie des fréquences optiques (FOP)
Site Web de l'équipe
Equipe : Métrologie des fréquences optiques (FOP)
Site Web de l'équipe
21/10/2024
/
Thèse :
Rémunération :
74
Training of superconducting analog quantum neural networks
Domaines
Quantum Machines
Quantum information theory and quantum technologies
Type de stage
Expérimental et théorique Description
Our team has recently demonstrated that a quantum reservoir neural network implemented on a circuit QED system composed of a transmon qubit coupled to a superconducting cavity can learn to classify input classical data. In this pilot experiment, neural outputs were obtained by measuring probability occupations of different Fock states of a single quantum oscillator and training was performed on a classical computer after the measurement. In order to perform harder learning tasks and increase the expressivity of the neural network, training should be done in the quantum system as well. For this, we are developing new training algorithms, specific to analog quantum systems.
The goal of the internship and subsequent PhD thesis is to simulate and implement layers of parametrized operations that will be applied on the quantum systems and whose parameters will be trained using physics aware learning methods.
Contact
Danijela Markovic
20/10/2024
/
Thèse :
Rémunération :
75
Quantum Control of Superconductor-Nanotube Hybrid Circuits
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
The quantum circuits in today’s processors primarily rely on Josephson tunnel junctions, consisting of two superconductors separated by a thin tunnel barrier. The supercurrent flowing through this barrier via tunneling gives the system nonlinear properties, allowing the isolation of two quantum states of a bosonic oscillator, which are used to encode quantum information.
In the QCMX group, we are developing alternative qubits based on another class of Josephson junctions. In our approach, the tunnel barrier is replaced by a quantum conductor made of a single molecule: a carbon nanotube. Due to its extremely small size, this conductor can trap individual electron, adding a fermionic degree of freedom to the natural bosonic degree of freedom of the qubit.
Our team has already demonstrated coherent control of the bosonic degree of freedom through Rabi and Raymsey oscillations, and independently observed the fermionic degree of freedom in the form of Andreev bound states. The goal of this internship is to further explore the interaction between these two degrees of freedom within our hybrid architecture.
This system offers unique perspectives, including the possibility of controlling a single fermion within a quantum device. In addition to providing a novel resource for quantum information encoding, this approach allows us to study electronic behavior in low-dimensional systems.
Contact
Jean-Damien Pillet
18/10/2024
/
Thèse :
Rémunération :
76
Quantum imaging using high harmonic states of light
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Metrology
Type de stage
Expérimental Description
Quantum imaging (QI) is a rapidly developing field of research with stunning progresses and emerging societal applications. Quantum-enhanced imaging schemes harness the beneficial properties of entangled photon pairs allowing transferring amplitude and phase information from one photon state to the other. The main objective of the internship will consist in using a pair of non-degenerated entangled photons at 2 harmonics from the high harmonic frequency comb to perform a quantum imaging experiment . We will study the possibility of transferring the sensing and resolution benefit from one spectral range to another one.
The quantum correlations between the two photons from the same harmonic generation process will be used to transfer amplitude and phase information between the two photons. Ultimately, the candidate will investigate novel protocols to create high-resolution label-free images of complex structures (e.g. cells) embedded inside biological tissues.
Contact
Hamed Merdji
18/10/2024
/
Thèse :
Rémunération :
77
Multipartite entanglement in semiconductor high harmonic generation
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Quantum information science and imaging technologies reach some bottleneck due to limited scalability of non-classical sources. Future breakthroughs will rely on high production rate of various quantum states in scalable platforms. Generally, multipartite entanglement with N>2 suitable for quantum applications is difficult to achieve because of the low efficiency of the traditional schemes. Intrinsically, the the process of high harmonic generation in semiconductors comes as a frequency comb and should exhibit N-partite entangled photons. Practically, the internship project will consist in extensively study the non-classical properties of the HHG process in a semiconductor for N>2. In the process, each emitted photon is a superposition of all frequencies in the spectrum, i.e., each photon is a comb so that each frequency component can be bunched and squeezed. The candidate will first develop and test entanglement and will verify genuine multipartite entanglement of the photons in the time/frequency domain. The approach will be further extended to verify multi-partite entanglement between even more optical modes.
Contact
Hamed Merdji
18/10/2024
/
Thèse :
Rémunération :
78
Multipartite entanglement in semiconductor high harmonic generation
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Quantum information science and imaging technologies reach some bottleneck due to limited scalability of non-classical sources. Future breakthroughs will rely on high production rate of various quantum states in scalable platforms. Generally, multipartite entanglement with N>2 suitable for quantum applications is difficult to achieve because of the low efficiency of the traditional schemes. Intrinsically, the the process of high harmonic generation in semiconductors comes as a frequency comb and should exhibit N-partite entangled photons. Practically, the internship project will consist in extensively study the non-classical properties of the HHG process in a semiconductor for N>2. In the process, each emitted photon is a superposition of all frequencies in the spectrum, i.e., each photon is a comb so that each frequency component can be bunched and squeezed. The candidate will first develop and test entanglement and will verify genuine multipartite entanglement of the photons in the time/frequency domain. The approach will be further extended to verify multi-partite entanglement between even more optical modes.
Contact
Hamed Merdji
18/10/2024
/
Thèse :
Rémunération :
79
Attosecond control of quantum states of light
Domaines
Quantum optics/Atomic physics/Laser
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Metrology
Type de stage
Expérimental Description
High-harmonic generation is a light up-conversion process occurring in a strong laser field, leading to coherent attosecond bursts of extreme broadband radiation. As a new paradigm, attosecond electronic or photonic processes such as high-harmonic generation (HHG) can potentially generate quantum states of light well before the decoherence of the system occurs. We recently reported the violation of the Cauchy-Schwarz inequalityas as a direct test of multipartite entanglement in the HHG process. The internship will consist in realizing a platform that will allow controlling the HHG quantum state on attosecond time scale, This opens the vision of quantum processing on unprecedented timescales, an evident perspective for future quantum optical computers. For M2 students: only candidates motivated to follow with a PhD in this topic will be considered. L3 and M1 students are welcome.
Contact
Hamed Merdji
18/10/2024
/
Thèse :
Rémunération :
80
Non-Euclidean photonics & Quantum chaos
Domaines
Quantum optics/Atomic physics/Laser
Relativity/Astrophysics/Cosmology
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Quantum information theory and quantum technologies
Quantum optics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Quantum chaos is a research field dedicated to semi-classical physics [1], ie. the relationship between a quantum system and its classical counterpart. The predictions are investigated in any wave system, namely quantum, acoustic, microwaves, optics,… One of the major hypothesis is the localization of eigenmodes on classical periodic trajectories.
Recently, we demonstrated the fabrication of surface-like microlasers by Direct Laser Writing (DLW). The laser modes were indeed located along periodic geodesics [2] (a geodesic is the shortest path between two points on a surface, like the straight line in Euclidean space). It opens the way to a new domain, called Non-Euclidean Photonics. In spherical squares, for instance, the geodesics are stable (Fig. bc). During the internship, the student will investigate microlasers based on a pseudosphere, a surface with constant negative curvature (Fig. e), where geodesics are unstable and the classical dynamics is chaotic [3].
The microlasers are fabricated by Dominique Decanini, the FDTD simulations are performed by Xavier Chécoury, the experiments are carried out by Mélanie Lebental, and the theory is developed by Barbara Dietz. The student will be involved in some of these tasks according to his/her likings.
Contact
Mélanie Lebental
18/10/2024
/
Thèse :
Rémunération :
81
Quantum Simulation with Ultracold Fermi gases
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum gases
Type de stage
Expérimental et théorique Description
From the promise of exponentially faster computers, new ways to transmit and store information, and vastly improved sensing capabilities, quantum science has become an extremely active area of research, providing a wide range of platforms, each with its particular strength. With quantum gases of ultracold atoms, experiments have had tremendous success in tackling quantum many-body problems, where unexpected and qualitatively new phenomena can emerge. These problems are notoriously complex owing to the large number of interacting particles, strong interactions, disorder, or nonlinear dynamics. This is the general context of this internship work.
Our group aims at understanding the behavior of strongly-interacting fermionic systems using an atom-based quantum simulator featuring single-atom imaging and manipulation capabilities. During this internship, you will take your first steps in the team by contributing with an experimental project (several options) with the perspective to join us as a PhD student in the Fall 2025.
Contact
Tarik Yefsah
18/10/2024
/
Thèse :
Rémunération :
82
Theoretical Electronic Structure and Excitonic Properties of Organic Topological Semiconductors
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
Band topology is now considered to be as fundamental as band structure, underlying emergent quasiparticle phenomena such as robust edge states and spin-chain physics in organic systems (e.g. graphene nanoribbons), but the impact of topological band structures on the physics of excitons (i.e. a correlated electron-hole photo-excited state bound by Coulomb interaction) has only recently begun to attract widespread attention. Understanding and controlling the effects of topological phase transitions on the electronic and optical responses of materials could become a powerful tool for the design of novel optoelectronic devices and future quantum technologies, and this project will explore topological effects in an exciting new class of organic 1D materials using state-of-the-art theoretical simulation methods.
Contact
Alex Chin
18/10/2024
/
Thèse :
Rémunération :
83
Quasi-1D Fermi gases
Domaines
Quantum gases
Type de stage
Expérimental et théorique Description
The internship will address some aspects of the physics of ultracold atoms confined in quantum waveguides, in a regime where their dynamics is quasi-one-dimensional and does not obey the usual paradigms of many-body physics in 3D.
Contact
Frédéric Chevy
Laboratoire : LPENS -
Equipe : Systèmes Classiques ou Quantiques en Interaction
Site Web de l'équipe
Equipe : Systèmes Classiques ou Quantiques en Interaction
Site Web de l'équipe
18/10/2024
/
Thèse :
Rémunération :
84
AC Conductivity in ultracold Fermi gases
Domaines
Condensed matter
Non-equilibrium Statistical Physics
Quantum gases
Type de stage
Théorique, numérique Description
The internship and the subsequent PhD will be devoted to the theoretical study of quantum transport in strongly correlated ultracold matter.
Contact
Frédéric Chevy
Laboratoire : LPENS -
Equipe : Systèmes Classiques ou Quantiques en Interaction
Site Web de l'équipe
Equipe : Systèmes Classiques ou Quantiques en Interaction
Site Web de l'équipe
18/10/2024
/
Thèse :
Rémunération :
85
Quantum engineering of light with intracavity Rydberg superatoms
Domaines
Quantum optics/Atomic physics/Laser
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Quantum gases
Type de stage
Expérimental et théorique Activité en entreprise
Description
Optical photons are excellent carriers of quantum information, but their lack of mutual interactions is a major roadblock for quantum technologies. We enable such interactions by transiently injecting the photons into an intra-cavity cold atomic gas and converting them into strongly interacting Rydberg polaritons. The Rydberg-blockaded cloud then acts as an effective two-level superatom with an enhanced coupling to light. We can coherently manipulate and efficiently detect its state, and use it to deterministically generate pulses of light with negative Wigner functions. This platform opens many perspectives for developing deterministic multi-photon gates, performing quantum measurements impossible with current techniques, generating non-classical optical resource states, and studying strongly correlated quantum fluids of light.
We recently expanded this setup towards the multi-superatom regime. A possible M2 internship will consist in studying the effective interactions between optical pulses reflected from the cavity with two superatoms, leading to a PhD project focused on deterministic multi-photon quantum logic and Wigner-negative light states generation. Another internship topic will focus on the design and construction of a new setup with single atoms trapped next to a superatom. The following experimental PhD thesis will aim at developing quantum interconnects between static and flying qubits, in a collaboration with the quantum tech company Pasqal.
Contact
Alexei Ourjoumtsev
17/10/2024
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Thèse :
Rémunération :
86
Test of quantum electrodynamics in strong Coulomb field
Domaines
Quantum optics/Atomic physics/Laser
High energy physics
Metrology
Type de stage
Expérimental et théorique Description
This internship will be centred in the preparation of a new experiment on high-accuracy x-ray spectroscopy of few electrons heavy ions for testing quantum electrodynamics (QED) in strong Coulomb field (the field of the highly charged ion).
On the one hand, to setup the acquisition system of the new detector and to make first tests with fluorescence targets and (possibly) with highly charged ions in our SIMPA installation in the Pierre et Marie Curie campus. On the other hand, the candidate will estimate the sensitivity to the nuclear size and deformation effects for the planned measurement to select the most interesting uranium isotopes to be studied. Some calculations will require the use of the MCDFGME code.
Contact
Martino Trassinelli
17/10/2024
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Thèse :
Rémunération :
87
Advancing Electron Spin Resonance Spectroscopy in the Realm of Quantum Technologies
Domaines
Condensed matter
Quantum information theory and quantum technologies
Type de stage
Expérimental Description
Join a cutting-edge project focused on advancing Electron Spin Resonance (ESR) technology! ESR is a powerful tool for studying materials with unpaired electrons, revealing critical insights in chemistry, biology, physics, nanosciences, and quantum mechanics. However, current commercial spectrometers require large sample sizes due to limited sensitivity, hindering small-scale research.
Our project plan to harness the recent breakthroughs of the superconducting quantum technologies at 10mK and extend them to a wider temperature range. We aim to develop an ESR spectrometer using high critical-temperature superconductor (HTS) microwave resonators. These HTS resonators promise to enhance spin sensitivity up to liquid nitrogen temperature, by bridging and thus overcoming the limitations of existing technologies.
As an intern, you’ll engage in designing, fabricating, and characterizing traditional metallic resonators, and later apply your expertise to HTS resonators. You’ll measure their microwave responses under cryogenic conditions (down to ~6K) and benchmark their performance against traditional resonators. Your work will push the boundaries of spin sensitivity, opening doors to studying innovative small-scale samples.
This hands-on experience will immerse you in the exciting realms of microwaves, superconducting technologies, quantum devices, and spin materials, potentially leading to publication and a financed PhD in this pioneering field.
Contact
Rémy Dassonneville
17/10/2024
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Thèse :
Rémunération :
88
QED fluctuation interactions`
Domaines
Statistical physics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
Explore the frontier of electromagnetic quantum effects in nano systems. One of the most striking predictions of quantum physics is the interaction of the electromagnetic vacuum with atoms and macroscopic bodies. Spectacular manifestations of this interaction are Casimir forces. Enormous progress in force sensing techniques and the fabrication of nano-structures have highlighted impressively the practical relevance of this quantum effect. This intern-ship concerns the use of new theoretical methods to study the interaction of atoms and molecules with nano-structures.
Contact
Thorsten Emig
Laboratoire : LPTMS - UMR 8626
Equipe : Disordered systems, soft matter, interface physics
Site Web de l'équipe
Equipe : Disordered systems, soft matter, interface physics
Site Web de l'équipe
17/10/2024
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Thèse :
Rémunération :
89
Producing optical potentials for ultracold atoms with a DMD
Domaines
Quantum gases
Type de stage
Expérimental Description
Exploiting the single-atom-resolved detection in momentum space [1], the Helium lattice team has studied and characterized interacting lattice Bose gases in three-dimension (3D) (see for instance [2]). A
fascinating feature of interacting lattice bosons is that they undergo a quantum phase transition
from a superfluid state to an insulator state, called a Mott insulator.
A main drawback of the configuration used so far in our experiment lies in the presence of a
harmonic trap: it implies that we probe gases with non-homogeneous atomic density and couplings
in the lattice. Since the physics of the Mott transition strongly depends on the spatial homogeneity
of these parameters, the study of the critical regime of the Mott phase transition is strongly
impaired. Our plan is to upgrade the apparatus to realize homogeneous samples and probe the
physics of the critical regime of the Mott transition.
We propose to combine the use of a high numerical aperture (NA) microscope - to shine optical
potentials with high resolution - with the use of a digital mirror device (DMD) to create arbitrary
patterns of optical potentials (see picture).
The aim of the internship consists in (i) characterizing the optical potentials created by the DMD,
(ii) conceiving the optical setup to address the atoms with the light potential reflected from the
DMD and, (iii) verifying the properties of the optical potentials on a test optical bench.
Contact
David CLEMENT
16/10/2024
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Thèse :
Rémunération :
90
Single Quantum Dot Nano-LEDS using Scanning Tunneling Luminescence
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Colloidal quantum dots (CQDs) are semiconductor nanoparticles that, due to their size (2-20 nm), fall in the quantum confinement regime. As such, they exhibit optical properties that can be continuously adjusted over a wide range of wavelengths, from the infrared to the ultraviolet. These objects are very good single photon sources at room temperature, capable of emitting photons one-by-one with high efficiency. Recently, diluted CQDs were integrated within electrical transport layers, allowing to observe electrically-injected single-photon emission. Nevertheless, the charge injection pathway is very complex in such devices involving a very large ensemble of CQDs, and brightness is very low as single photon purity is achieved by collecting photons from a very limited area.
In this internship, we propose to use scanning tunneling electroluminescence microscopy (STLM) to probe electronic and optical properties of CQDs with nanoscale resolution, essentially realizing a true single-CQD LED inside a STM equipped with light collection optics. The goals are:
(1) probe the local electronic density of state at the single CQD level using to tunneling spectroscopy, correlate such measurements with collected electroluminescence and with ensemble optical spectroscopy;
(2) build a Hanbury-Brown and Twiss interferometer (HBT) and observe single photon emission excited by tunnel currents in single CQDs;
(3) provide an accurate description of the charge injection mechanism.
Contact
Alistair Rowe
16/10/2024
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Thèse :
Rémunération :
91
Light in Complex Media : from imaging to computing
Domaines
Quantum optics/Atomic physics/Laser
Quantum Machines
Quantum information theory and quantum technologies
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Scattering of light in heterogeneous media, for instance the skin or a glass of milk, is usually
considered an inevitable perturbation or even a nuisance. Through repeated scattering and
interferences, this phenomenon seemingly destroys both the spatial and the phase information
of any laser illumination.By « shaping » or « adapting » the incident light, it is in principle possible to control the propagation and overcome the scattering process. This concept has been exploited in the last decade to focus and image through and in complex media, and opens important prospects for imaging at depth in biological media.
In the group we are currently exploring two main topics, combining synergistically optical design and numerical studies for : (a) non-invasive coherent (SHG, Raman) and incoherent (multiphoton fluorescence) imaging, leveraging computational microscopyconcepts and (b) exploiting random mixing induced by the propagation of light through a complex medium for various computational tasks, allowing the intriguing concept of computing with disorder.
We have multiple funded ongoing projects along these two directions and welcome motivated
applicants for internship, with a solid background in physics, and an interest in machine learning, optics, imaging and computing.
Contact
Sylvain Gigan
16/10/2024
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Thèse :
Rémunération :
92
Solving strongly correlated electrons of real systems with quantum computing: application to oxydes
Domaines
Condensed matter
Quantum information theory and quantum technologies
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Activité en entreprise
Description
Atomic scale simulations play a central role to understand and anticipate the ageing of materials for low-carbon
energy such as batteries or steels inside nuclear reactors. The successful Density Functional Theory is the state-of-the-art
method to tackle these bulk materials but still fails to reach physically interesting phenomena such as paramagnetism in
austenitic steels or strongly correlated electrons in oxydes. Meanwhile, quantum computing is foreseen to solve industrial
materials problems but algorithms developed today in the Noisy Intermediate Scale Quantum (NISQ) era have only been
tested on small or toy models. In addition, the ultimate goal of outperforming classical algorithms benefiting from dozen of
years of optimisation is still out of reach.
In this internship, we will combine advanced quantum chemistry methods (embedding
methods such as Density Matrix Embedding Theory-DMET) and quantum computing where the solving part will be a
quantum algorithm that can be run on a quantum computer. Your work will be to design an innovative approach namely
the quantum embedding method to solve NiO oxyde such as in (Cao et al., 2023) and to compare numerical results of this
algorithm with best classical methods. The effect of noise might be explored. This internship is planned to be pursued in a
PhD CIFRE.
Contact
Antoine Michel
Laboratoire : Matériaux et Mécanique des Composants (MMC) -
Equipe : Métallurgie
Site Web de l'équipe
Equipe : Métallurgie
Site Web de l'équipe
16/10/2024
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Thèse :
Rémunération :
93
Painted optical potentials for ultra cold gases in microgravity
Domaines
Quantum optics/Atomic physics/Laser
Quantum gases
Metrology
Type de stage
Expérimental Description
To produce a Bose-Einstein condensate, an optical tweezer traps the atoms in a high vacuum chamber at the focused point of a far-red detuned laser. One originality of our set up is the ability to modulate spatially the position of the highly focused laser beam.
The objective of this internship is to develop a new optical bench to improve this painted potential, by extending the technique in 3D. Based on spatial modulation in 2D dimensions using two crossed acousto-optical modulators, it will create a 3D painted potential in a crossed configuration. Special care will be taken about the robustness of the system which has to be compliant with the zero-g simulator. The implementation in the microgravity experiment is planned for a potential Ph. D in the group after the internship.
Contact
Baptiste BATTELIER
16/10/2024
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Thèse :
Rémunération :
94
Heat transport in confined metal nanowires
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
In this internship, we will explore a novel technique that allows us to directly probe the thermal behavior of nanomaterials at unprecedented scales. Recent advances in event-based direct detectors in electron microscopy [1] open new possibilities. At the LPS Orsay, a new method based on synchronized focused-photon excitation and electron scattering of nanostructures [2] allows for temperature measurements with nanosecond and nanometer resolution [3]. In this M2 internship we will explore this new technique to measure the thermal transport properties of nanoscale metallic nanowires.
This internship will involve the production of metallic nanowires using electron beam lithography and metal evaporation, the realization of electron spectroscopy in a state-of-the-art electron microscope, including world-wide unique light injection experiments, and data modeling for thermal transport. The ideal candidate will have a strong background in solid-state physics, with a focus on experimental techniques. Experience with data analysis tools (specifically Python) is essential. Familiarity with thermal transport theory and modeling would be a plus.
References
[1] Y. Auad et al., Ultramicroscopy 239 (2022) 113539; Y. Auad, et al., Ultramicroscopy 257 (2024) 113889.
[2] Y. Auad, et al., Nat. Comm. 14 (2023) 4442; N. Varkentina et al. Sci. Adv. 8 (2022) eabq4947.
[3] F. Castioni, et al., in preparation (2024).
Contact
Luiz Tizei
16/10/2024
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Thèse :
Rémunération :
95
New quantum sensor concepts for measuring gravity on antihydrogen.
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Metrology
Type de stage
Théorique, numérique Description
For several years now, the Kastler Brossel laboratory has been studying the possibility of using the quantum bounce of an atom, thanks to the Casimir Polder potential, to produce atomic interference and a precise measurement of gravity. Until now, models have neglected surface losses. We want to take them into account and calculate their effect on the interference. This theoretical project will be based mainly on numerical simulations and analytical models.
Contact
Pierre Cladé
15/10/2024
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Thèse :
Rémunération :
96
Next generation of quantum sensors based on atom interferometry
Domaines
Quantum optics/Atomic physics/Laser
Metrology
Type de stage
Expérimental Description
Atom interferometry is a key tool for developing high-precision quantum sensors. The Kastler Brossel Laboratory is a world leader in this field. Thanks to its work on measuring recoil velocity through atomic interferometry, it has provided the most accurate determination of the fine-structure constant α.
We are offering two experimental internship subjects, each of which could lead to a doctoral thesis.
The first concerns the construction of a large momentum transfer beam splitter on a rubidium atom interferometer.
The second subject concerns the construction of an interferometer using Ytterbium atoms
Contact
Pierre Cladé
15/10/2024
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Thèse :
Rémunération :
97
Nano-imaging of non-Fourier heat flow
Domaines
Condensed matter
Hydrodynamics/Turbulence/Fluid mechanics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Efficient heat management is critical for the optimal performance and energy consumption of modern-day electronics. While Fourier’s macroscopic model for heat diffusion has been a valuable tool for homogeneous solids at room temperature, it falls short in describing heat propagation accurately under certain conditions. This PhD project aims to quantitatively investigate scenarios where the Fourier model breaks down and work towards developing a more physically satisfying model of heat propagation. In particular, this project will focus on the phonon viscous hydrodynamic transport regime that has recently attracted considerable interest in the scientific community. It is a regime that is neither ballistic nor diffusive and emerges when quasi-particles interact strongly with each other without loosing momentum.
The goal of this PhD will be to build a very sensitive and local thermometer (based on SQUID technology) so as to map out the temperature distribution at a few tens of nm to look for signatures of this non-Fourier like behaviour.
As a PhD researcher, you will participate in the design, construction and operation of the SQUID based microscope. Enthusiasm for instrumentation is necessary.
The PhD can be funded for 3 years, starting in Fall 2025 (no later than 01/11/2025).
Applications are accepted on an ongoing basis until the position is filled.
Contact
Arthur Marguerite
15/10/2024
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Thèse :
Rémunération :
98
Emergent quantum computation from the dynamics of complex systems
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Fields theory/String theory
Quantum Machines
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Non-equilibrium Statistical Physics
Type de stage
Théorique, numérique Description
Investigating innovative approaches to analog computing by harnessing the emerging dynamics of quantum systems represents an exciting and modern frontier. This endeavor holds the potential to transform domains such as optimization, machine learning, and simulations by addressing complex problems that classical computers struggle to solve. It introduces a new computational paradigm applicable to fields like optimization, artificial intelligence, and scientific simulations, offering the promise of improving the efficiency and effectiveness of solving intricate real-world challenges.
During this theoretical internship, the Master's student will learn, generalize, and apply methods developed in recent and promising works to explore innovative and advanced strategies for utilizing the intricacies of quantum systems. The goal is to develop emergent computational capabilities, particularly aimed at solving optimization problems and tackling interdisciplinary challenges. The internship’s theoretical research will involve both analytical and numerical methods, with a focus on the quantum many-body physics of state-of-the-art quantum platforms, including superconducting quantum circuits and other quantum systems. This is an internship proposal that can continue into a PhD thesis.
Contact
Cristiano Ciuti
15/10/2024
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Thèse :
Rémunération :
99
Many-body effects in silicon & germanium spin qubits
Domaines
Condensed matter
Low dimension physics
Quantum information theory and quantum technologies
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
Silicon & Germanium spin qubits have made outstanding progress in the past few years. In these devices, the elementary information is stored as a coherent superposition of the spin states of an electron or hole in a quantum dot. These spins can be manipulated electrically owing to spin-orbit coupling, and are entangled through exchange interactions, allowing for a variety of one- and two-qubit gates required for quantum computing and simulation. Grenoble is developing original spin qubit platforms on Si and Ge, and holds various records in spin lifetimes and spin-photon interactions. At CEA Grenoble, we support the progress of these advanced quantum technologies with state-of-the-art modelling. In particular, we are developing the TB_Sim code, able to describe very realistic qubit structures down to the atomic scale.
The role of Coulomb interactions in spin qubits remains poorly understood. Quantum dots with 3 to 5 electrons or holes are expected to screen noise & disorder better than singly-occupied ones; yet Coulomb interactions can dramatically reshape the spectrum and dynamics of the system (Wigner localization…). The aim of this master training is, therefore, to model the effects of Coulomb interactions on spin qubits using “configuration interaction” methods for the many-body wave functions, in relation with ongoing experiments in the lab. This Master thesis may be followed by a PhD project on spin manipulation and entanglement in arrays of spin qubits.
Contact
Yann-Michel Niquet
15/10/2024
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Thèse :
Rémunération :
100
Quantum transport of charge and heat in non-abelian quantum hall states of graphene
Domaines
Condensed matter
Low dimension physics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Even-denominator states of the fractional quantum Hall effect (e.g. 𝜈=5/2) are expected to host excitations that have non-abelian anyonic statistics, corresponding to quantum particles that are neither bosons nor fermions, and the ground state of which changes orthogonally upon exchanging two identical particles. Non-abelian anyons are promising candidates for the realization of topological quantum computing; however, demonstrating the existence of non-abelian statistics is an extremely challenging task, requiring advanced experiments such as interferometry, collisions, and thermal transport measurements. So far, only the latter has been achieved, in only a single system: high-mobility semiconductor GaAs heterostructures. In this project, we propose to implement heat transport and collision experiments, in bilayer graphene, which has recently been shown to host a large number of even-denominator states much more robust than in GaAs, that are thought to be non-abelian. Performing those experiments in bilayer graphene will allow demonstrating the universality of the properties of non-abelian anyons.
This internship, which is planned to be followed by a PhD, involves advanced experimental techniques, including the nanofabrication of ultra-clean bilayer graphene samples in van-der-Waals heterostructures and ultra-high sensitivity thermal and noise measurements at very low temperatures and high magnetic field.
Contact
François Parmentier
14/10/2024
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Thèse :
Rémunération :
101
Superconducting Devices in Silicon
Domaines
Condensed matter
Low dimension physics
Quantum information theory and quantum technologies
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
The project focuses on the study of superconducting devices with silicon as a semiconductor. Those include standard silicon transistors with superconducting source and drain contacts and superconducting resonators. The common properties is the superconducting material which is elaborated with the constrain of being compatible with the silicon CMOS technology.
In the actual situation of the project, devices with CoSi2, PtSi and Si:B superconducting contacts have been fabricated using the 300 mm clean room facility at the LETI and in collaboration with our partners at Uppsala university and C2N Paris Saclay. The main issue is now to characterize the electronic transport properties at very low temperature. Depending on the quality of the contact interface between the S/D contacts and the silicon channel, various behavior are expected. In the case of opaque contacts, the current at very low S/D bias is blocked due to the opening of the superconducting gap. In the opposite case, superconducting correlations extend in the channel and a gate-tunable non-dissipative supercurrent is expected to flow though the transistors. This situation, met for other materials like germanium (see other master project on protected qubit ), is the ultimate goal of the project.
The master internship will focus on measurements at very low temperature of existing devices.
Contact
François Lefloch
14/10/2024
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Thèse :
Rémunération :
102
Photonic Crystal Cavities for Terahertz Biosensing
Domaines
Condensed matter
Biophysics
Low dimension physics
Physics of living systems
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Metrology
Type de stage
Expérimental Description
THz waves, typically between 0.1 THz and 10 THz, have great potential for a wide range of biomedical diagnostic applications, as well as for the fundamental study of a variety of biomolecules. Indeed, many biomolecules and biomolecular complexes exhibit relevant intramolecular and intermolecular resonances in this frequency range, paving the way for a wide range of biomedical and diagnostic applications. THz biosensing is therefore a fast-growing field of research. An extraordinary advantage of THz spectroscopy for biological applications is that it enables direct, label-free probing of the interaction of biomolecules with THz radiation.
The aim of this internship is to develop original THz photonic crystal cavities offering a high THz electric field concentration with an ultra-high quality factor, and thus optimized for high-sensitivity THz biosensing. Òur group has recently realized THz cavities providing high electric field confinement with a quality factor of a few tens but limited by the use of metals with ohmic losses. To overcome these limitations, the candidate will realize dielectrically patterned, metal-free, THz photonic crystal cavities that will be further implemented into THz biosensors, to come closer to today's state-of-the-art bioanalytical tools. The candidate will design the photonic crystal cavities using simulations based on finite element method, participate to their fabrication and investigate their optical properties using THz spectroscopy systems.
Contact
Juliette MANGENEY
11/10/2024
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Thèse :
Rémunération :
103
Semiconductor saturable absorber mirrors for mid-IR fiber and cascade laser combs
Domaines
Condensed matter
Low dimension physics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Saturation of the light-matter interaction is a general nonlinear feature of materials: atoms or semiconductors. In semiconductors, controlling saturation phenomena is important for fundamental physics and applications. A seminal example is the semiconductor saturable absorption mirror (SESAM), that revolutionized ultra-fast lasers in the vis/near-IR spectral range.
In the mid-IR (lambda=3-30 um), the intensity required for saturation is high, about 1 MW/cm2. This high value explains why SESAM mirrors are missing from the toolbox of mid-IR opto-electronics.
The host team proposed that absorption saturation can be engineered if the system operates in the strong light-matter coupling regime, and provided an experimental proof.
The team designed SESAMs with low saturation intensities: the goal is generating mid-IR frequency combs with tabletop fiber or interband cascade lasers.
The goal of the internship is to develop low-power SESAMs in the mid-IR, supported by recently obtained results, that suit the comb application with fiber and/or cascade lasers. Experiments will be performed by optical pumping with a tunable QC laser in an existing experimental setup.
If time permits, time domain characterizations will be performed with a mid-IR pump/probe setup.
This project evolves in the context of a running ANR grant and of an ERC Advanced grand. It opens up exciting perspectives in the realization of ultrafast, mode-locked mid-IR fiber and semiconductor lasers.
Contact
Raffaele Colombelli
11/10/2024
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Thèse :
Rémunération :
104
Ultra-fast mid-IR modulators for applications to frequency combs and spectroscopy
Domaines
Condensed matter
Low dimension physics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Electrically reconfigurable surfaces are artificial components whose optical properties (reflection, absorption) can be addressed electrically. They are particularly useful as amplitude or phase modulators.
In the mid-infrared (MIR, 3um<lambda<30um), these functionalities are useful for applications such as laser phase stabilization, spectroscopy, EO frequency comb generation.
The ultrafast (10–40GHz) modulation of MIR radiation is a missing device functionality. The Host Team is at the forefront of research with a far-reaching approach: the development of electrically reconfigurable surfaces for the MIR.
The Host Team recently demonstrated ultra-fast MIR modulators with performances that are compatible with real world applications.
The specificity (and the beauty) of the concept is that it relies on a fundamental physics phenomenon: the strong-coupling regime between light and matter.
The goal of this internship is: (i) employing the currently existing modulators to generate EO frequency combs, a crucial step for applications. (ii) participate in the full characterization, and result interpretation, of a new generation of modulators with improved functionalities.
The experiments will be performed with the existing setup, built around a tunable quantum cascade laser. The perspective intern will also have the possibility to add improvements to the setup (for instance the measurement of the modulation phase).
Contact
Raffaele Colombelli
11/10/2024
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Thèse :
Rémunération :
105
Coupling of Josephson currents and magnetization dynamics is S/F hybrids
Domaines
Condensed matter
Type de stage
Expérimental Description
The interplay between superconductivity and magnetism has attracted the attention of physicists for years. The coupling between magnetization dynamics and the superconducting state constitutes a pivotal topic, because of its fundamental interest and its relevance in the nascent field of ”superconducting spintronics”.
The spin dynamics can be excited by ferromagnetic resonance (FMR), particularly by shining microwaves that excite the magnetization precession of the macroscopic-magnetic moment. If the ferromagnet is connected to two superconducting electrodes, and these are close enough, this precession of the magnetization expectedly yields the condition for the generation of unconventional superconducting spin-triplets, thus allowing for Josephson coupling across the ferromagnet. The internship is devoted to experimentally verifying this theoretical prediction, and investigating how spin pumping into the superconductor interplays with Josephson coupling. The existing literature on S/F hybrids most often studies (low-Tc) s-wave superconductors. Instead, here we propose (high-Tc) d-wave ones, which are up to now unexplored in this context and display many unique properties. For example, an anisotropic gap results in a high density of QP (Andreev) bound states at the Fermi level.
This internship and the PhD thesis that should follow will focus on understanding the different mechanisms at play, and the potential of these effects for spintronic applications.
Contact
Javier Villegas
11/10/2024
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Thèse :
Rémunération :
106
Quantum inspired algorithms meet artificial intelligence
Domaines
Condensed matter
Quantum Machines
Quantum information theory and quantum technologies
Type de stage
Théorique, numérique Description
Quantum computers are expected to change computations as we know it. How are they supposed to do that? Essentially they allow us to perform a subpart of linear algebra (certain matrix-vector multiplications) on exponentially large vectors. A natural mathematical famework to understand what they do is the tensor network formalism. Conversally, tensor networks are becoming popular as tools that can take the place of quantum computers, yet run on perfectly classical hardware. To do so, they rely on a hidden underlying structure of some mathematical problems (a form of intrication) that can be harvested to compress exponentially large vectors into small tensor networks. An increasing number of, apparently exponentially difficult, problems are getting solved this way.
This internship lies at the intersection between theoretical quantum physics and applied mathematics. The goal will be to develop and apply new algorithms to “beat the curse of dimensionality”, i.e. to push the frontier of problems that we are able to access computationally. More specifically, we will explore a new approach to address a class of high dimensional integrals that arise in the context of Feynman diagram calculations [1]. The envisionned algorithms combine the normalization flow approach (from neural networks) with the tensor cross interpolation (from tensor networks).
[1] https://journals.aps.org/prx/abstract/10.1103/PhysRevX.10.041038
Contact
Xavier Waintal
11/10/2024
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Thèse :
Rémunération :
107
Study of color centers in 2D materials for quantum sensing
Domaines
Condensed matter
Low dimension physics
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
This project aims to overcome these limitations through the design of a new flexible quantum sensor based on an atomically-thin two-dimensional (2D) material. To this end, we will study the magneto-optical properties of recently discovered spin defects in 2D hexagonal boron nitride (hBN) also known as white graphene.
The internship work aims at building a state-of-the-art optical setup to measure quantum properties of color centers in hBN. This will include the development of a Hanbury Brown and Twiss measurement setup to assess the single photon nature of the emitters and the measurement of their spin relaxation and coherence times.
This project makes a bridge between two vibrant fields of research in condensed matter: (i) point defects for quantum technologies and (ii) 2D materials beyond graphene. It is expected to have strong and broad impacts for applied science (printed electronics, spintronics, optoelectronics …) and from the point of view of fundamental physics.
This experimental work will benefit from the state-of-the art facilities and the world-recognized expertise of LPCNO Toulouse for the fabrication of atomically thin materials and their study by advanced optical spectroscopy tools. In particular, the candidate will have the opportunity to work with tunable wavelength lasers, liquid Helium magneto-cryostats and single photon detectors.
Contact
Cedric ROBERT
10/10/2024
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Thèse :
Rémunération :
108
Magneto-ionic gating in magnetic tunnel junctions
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Magneto-ionics is an emerging field that offers great potential for reducing power consumption in spintronics memory applications through non-volatile gate-control of magnetic properties. By combining voltage-controlled ionic motion from memristor technologies, typically used in neuromorphic applications, with spintronics, magneto-ionics also provides a platform to create a new generation of neuromorphic computing functionalities based on spintronics devices. Our group has been at the forefront of investigating the magneto-ionic control of magnetic properties in various materials and nanodevice geometries. We have demonstrated gating effects on magnetic anisotropy and the Dzyaloshinskii–Moriya interaction and characterised in depth the interactions between the mobile ions and the magnetic atoms.
One major challenge remains ahead for the use of magneto-ionics in practical applications, its integration into magnetic tunnel junctions (MTJ), the building blocks of magnetic memory architectures. This will not only unlock the dynamic control of switching currents in magnetic tunnel junctions to reduce power consumption in memory technologies, but also allow for the modulation of stochastic magnetisation switching, which has important implications in probabilistic computing.
We are currently seeking a highly motivated candidate to join our team at C2N and work on an experimental research project focused on the implementation of magneto-ionic gating schemes in MTJs.
Contact
Liza Herrera Diez
10/10/2024
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Thèse :
Rémunération :
109
Cavity-enhanced superfluorescence of perovskite nanocrystals superlattices
Domaines
Condensed matter
Low dimension physics
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Since their first synthesis in 2015, perovskite nanocrystals have attracted much attention due to their easy and cheap large-scale fabrication, and excellent optical properties for optoelectronics and quantum optics applications. A key breakthrough occurred in 2018 when superfluorescence was observed in superlattices of CsPbBr3 nanocrystals at low temperatures. Superfluorescence, a phenomenon where emitters synchronize through their long-range interaction and emit a burst of coherent light, had previously been limited to atoms and a few solid-state systems due to the difficulty of obtaining identical individual emitters at high densities within a superstructure. Perovskite nanocrystals, with their narrow size dispersion, provide an ideal material for creating superlattices that can achieve this effect. Integrating these superlattices into optimized optical microcavities is also crucial for enhancing superfluorescence through cavity quantum electrodynamics effects. In the Nano-optics group, a fibered Fabry-Perot microcavity was designed to enhance the emission of solution-processed nanoemitters. The goal of the project is to couple perovskite nanocrystal superlattices to this microcavity and study the superfluorescence in free space and cavity configurations. Enhanced dipole-dipole coupling within the cavity is expected to involve more nanocrystals in the superfluorescence, leading to increased emission.
Contact
Carole Diederichs
09/10/2024
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Thèse :
Rémunération :
110
Quantum sensing of the 21 cm hydrogen line
Domaines
Condensed matter
Relativity/Astrophysics/Cosmology
Quantum Machines
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental et théorique Description
The 21 cm hydrogen line is a crucial resource for radioastronomy. The hydrogen element has witnessed many important epochs in the early Universe. The full spectrum of the hydrogen line arising from the red shifted emissions is therefore a highly sought for resource for cosmology and radioastronomy.
In this project which can lead to a PhD, we will use the tools of quantum sensing using superconducting circuits to probe the 21 cm line first for low redshifts and devise techniques to extend this to lower frequencies, suitable for understanding important questions in particular related to dark matter in the early Universe during the Cosmic Dawn.
Contact
Takis Kontos
09/10/2024
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Thèse :
Rémunération :
111
Etude d’une double source d’atomes froids pour un gyromètre à onde de matière
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum gases
Metrology
Type de stage
Expérimental et théorique Description
La manipulation d’atomes par laser permet de réaliser des interféromètres à onde de matière très sensibles à l’accélération et à la rotation. Il est ainsi possible de réaliser des capteurs extrêmement précis permettant par exemple de déterminer le champ de gravité terrestre ou de réaliser des tests de physique fondamentale. Actuellement, l’ONERA développe une centrale inertielle qui permet de mesurer simultanément les accélérations et les rotations et ainsi de remonter à sa position et son orientation sans utiliser le GPS. Des expériences de laboratoire ont démontré que la technologie quantique était très prometteuse pour ce type d’instrument. Cependant, plusieurs verrous scientifiques et technologiques empêchent actuellement de réaliser un capteur compact et embarquable utilisable en pratique.
Le stage que nous proposons porte sur la levée d’un de ces verrous qui est la réalisation dans un dispositif compact de la double source d’atomes froids nécessaire à une mesure de rotation précise. En particulier, le stagiaire étudiera une technique permettant de séparer en deux un nuage d’atomes froids issu d’un piège magnéto-optique à l’aide de réseaux optiques mobiles. Le stagiaire réalisera dans un premier temps une simulation numérique de l’interaction d’un nuage d’atomes froids avec les lasers, puis participera à sa mise en œuvre sur notre dispositif expérimental. Le stage pourra se poursuivre par une thèse sur le développement d’un gyromètre à atomes froids embarquable.
Contact
Yannick Bidel
08/10/2024
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Thèse :
Rémunération :
112
Dissipation and Decoherence in a Quantum System
Domaines
Condensed matter
Quantum Machines
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Quantum information theory and quantum technologies
Type de stage
Expérimental Description
http://tiny.cc/QG
What happens to the ground state of a quantum system when we add dissipation? How is the lifetime of excited states affected by dissipation? How is quantum coherence destroyed by dissipation? The student will measure the lifetime and coherence of a bad qubit: a Josephson junction shunted by an on-chip resistance and embedded in a superconducting microwave cavity. The student is expected to aid in the design of devices using microwave simulation software; fabricate samples in a clean room using techniques such as microlithography and electron beam evaporation; cool samples using a cryogen free dilution cryostat; and make sensitive microwave measurements at low temperatures
Contact
Çağlar Girit
08/10/2024
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Thèse :
Rémunération :
113
High quality superconducting resonators arrays for spin circuit quantum electrodynamics
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Expérimental Description
Quantum computing is currently pushing further the frontier of information technology. Among other fields, solid-state hole-spin qubits are a promising research area. Recently, we reached the strong-coupling regime between the spin of a single hole trapped inside the channel of a silicon transistor and a single microwave photon enclosed in a superconducting resonator [1], realizing a hybrid spin cQED architecture.
The aim of this project is to advance the field of spin cQED by fabricating superconducting resonator arrays made of superconducting thin films of NbN [3,4]. These arrays should allow to study the interaction between one spin and several microwave photonic modes, a first step toward quantum simulation. During the master project, you will participate to the development of new high quality resonators, which includes designing, modelling and measuring them.
Our research team is part of the French national “Plan Quantique” and we strongly collaborate with in-house theory colleagues.
During the master project, you will collaborate on a daily basis with a lively team of three permanent researchers and three PhDs. You will participate to the development of new samples and you will learn to cool down samples to reach cryogenic temperatures. State-of-the-art DC and RF measurements will be used.
[1] Nat. Nano 18, 741, 2023
[2] Phys. Rev. A 75, 032329, 2007
[3] Appl. Phys. Lett. 118, 054001, 2021
[4] arXiv:2403.18150, 2024
Contact
Xavier Jehl
08/10/2024
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Thèse :
Rémunération :
114
Ultra-strong coupling of a hole spin to a microwave photon
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Type de stage
Expérimental Description
Quantum computing is currently pushing further the frontier of information technology. Among other fields, solid-state hole-spin qubits are a promising research area. Recently, we reached the strong-coupling regime between the spin of a single hole trapped inside the channel of a silicon transistor and a single microwave photon enclosed in a superconducting resonator [1], realizing a hybrid spin cQED architecture.
The aim of this project is to further increase the coupling strength between the hole spin and the microwave photon to reach the ultra-strong coupling regime, a regime of light-matter interaction largely unexplored. First, we will probe this unique quantum system via microwave spectroscopy measurements [2]. In parallel, we will explore how time-domain experiments can unlock the peculiar physics of an ultra-strongly coupled spin to a microwave photon [3, 4].
Our research team is part of the French national “Plan Quantique” and we strongly collaborate with in-house theory colleagues.
During the master project, you will collaborate on a daily basis with a lively team of three permanent researchers and three PhDs. You will participate to the development of new samples and you will learn to cool down samples to reach cryogenic temperatures. State-of-the-art DC and RF measurements will be used.
[1] Nat. Nano 18, 741, 2023
[2] Phys. Rev. A 75, 032329, 2007
[3] Nat. Rev Phys. 1, 19, 219
[4] Rev. Mod. Phys. 91, 025005, 2019
Contact
Xavier Jehl
08/10/2024
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Thèse :
Rémunération :
115
Mixed dimensions van der Waals hetero-structures as a plateform for quantum photonics
Domaines
Low dimension physics
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
In recent years, carbon nano-emitters like nanotubes, graphene quantum dots, and nanoribbons have emerged as promising platforms for quantum photonics, particularly in quantum communication and information processing. Their optical properties are versatile, thanks to control over the working wavelength via quantum confinement. Methods such as chemical grafting of color centers in carbon nanotubes and chemically synthesized graphene dots have made these emitters more robust, with room-temperature single-photon emission demonstrated.
However, their performance is often hindered by environmental interactions, leading to dephasing and spectral diffusion. A promising solution is encapsulating nano-emitters in van der Waals heterostructures, which provide an atomically clean environment without needing ultra-vacuum conditions. Conductive 2D materials like graphene also allow for gating, reducing spectral diffusion by screening electrostatic fluctuations.
The research group has developed a cryogenic micro-photoluminescence setup, incorporating super-resolution techniques to map single-photon emitters with sub-wavelength precision (~20 nm). Quasi-resonant excitation spectroscopy further explores confined excited states.
This internship aims to deepen understanding of these heterostructures’ photophysics using advanced spectroscopy, with potential exploration of inter-layer excitons that could lead to new physics phenomena and applications like non-classical light sources.
Contact
Yannick Chassagneux
08/10/2024
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Thèse :
Rémunération :
116
Deep sub-wavelength dielectric cavities coupled to nano-emitters in the cavity quantum electrodynamics regime.
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
This scientific project focuses on coupling nano-emitters to optical micro-cavities, with potential applications in quantum telecommunication and advanced photonics. One key application is the Purcell effect, which accelerates the spontaneous decay rate and funnels photons into a single optical mode.
The strength of light-matter coupling depends on the ratio of the quality factor to the cavity mode volume. Two approaches exist to optimize this: the plasmonic route, which achieves sub-wavelength mode volumes but suffers from Ohmic losses, and the dielectric resonator route, which attains high Q but is limited by the diffraction limit. This project proposes to combine the strengths of both approaches by designing modified dielectric cavities that achieve high Q with sub-wavelength volumes using near-field techniques.
These cavities will couple with solid-state nano-emitters, such as carbon nanotubes or graphene quantum dots, to create artificial atoms for quantum technology applications. By utilizing the discontinuities of the electric field in a dielectric bow-tie antenna, the project aims to create ultra-small mode volumes. Coupling nano-emitters to these cavities requires spatial and spectral matching, achieved through open-cavities with a mirror on the tip of an optical fiber. The bow-tie antenna will be fabricated on this fiber, and the project focuses on designing, nanofabricating, and testing these antennas.
Contact
Yannick Chassagneux
08/10/2024
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Thèse :
Rémunération :
117
Edge magnetoplasmon interferometers
Domaines
Condensed matter
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Edge magnetoplasmon are the elementary collective excitations of quantum Hall systems and live on the chiral edge states that carry the current. In a closed loop configuration i.e., a Hall island, the EMPs enter a resonant mode corresponding to the ratio of the velocity and the perimeter of the island. In recent works we have studied such objects and showed that we were able to manipulate their geometric properties so as to influence the resonance condition. We have also made it clear how finite-size effects manifest in this system.
This internship will focus on the next step of this research that aims at realizing a rf interferometer in Hall systems. The experiment is based on the addition of a quantum point contact (QPC) to the structure that would separate the resonators in two lobes contacted through the QPC where quasiparticles exchange can happen. The path of EMPs in each cavity would thus lead to an interference of the signal that would in turn lead to a modulation of the transmission signal as a function of the threaded Aharonov-Bohm flux. The long-term objective of the project is to study anyons in fractional quantum Hall systems using this interferometer.
Contact
Gerbold Ménard
07/10/2024
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Thèse :
Rémunération :
118
Delta Kick Squeezing for Atom Interferometry beyond the Standard Quantum Limit
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum gases
Metrology
Type de stage
Expérimental Description
The aim of this intership is the implementation of the "Delta-Kick squeezing" (DKS) technique, which relies on the engineering of atom atom interactions in a BEC in free fall. Such interactions induce strong correlations between the atoms, and lead to squeezing in the population difference between the two interferometer paths, and eventually to phase sensitivity below the standard quantum limit.
Contact
Franck Pereira dos Santos
04/10/2024
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Thèse :
Rémunération :
119
On-chip Terahertz Spectroscopy of 2D Materials
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
In the recent years, the study of 2D materials such as the transition metal dichalcogenides (TMD) has led to the discovery of novel quantum states of matter. However, the fabrication of these materials often leads to small samples (~um) which can limit the range of tools used for their study and applications. This is the case of terahertz (THz) spectroscopy which, though limited by diffraction (~300 um), would be a powerful tool because the THz frequency range lies in the same energy range as many electronic excitations in these quantum materials.
In this Master project, we propose to develop a method to perform spectroscopy on micrometer scale 2D materials beyond the current diffraction limitation of standard THz spectroscopy. This new technique uses “on-chip” generation and detection of THz pulses and will allow the candidate to study NbSe2, an exotic SC hosting simultaneously SC and a charge-density-wave (CDW) state. NbSe2 samples will be progressively exfoliated and measured down to the ultimate monolayer 2D limit. These already unprecedented results will pave the way for a PhD thesis for which the candidate will implement pump-probe “on-chip” THz spectroscopy, investigating the dynamics and interaction of the Higgs and CDW modes when driven far away from equilibrium and the possibility of inducing long-lived metastable SC states in this system.
Contact
Romain Grasset
Laboratoire : Laboratoire des solides irradiés - UMR 7642
Equipe : New electronic states - TeraX-lab
Site Web de l'équipe
Equipe : New electronic states - TeraX-lab
Site Web de l'équipe
04/10/2024
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Thèse :
Rémunération :
120
Mesoscopic quantum electrodynamics with spins in carbon nanotubes
Domaines
Condensed matter
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental Description
The HQC group recently demonstrated the manipulation, with cavity photons, of quantum states in a carbon nanotube (CNT) with coherence time of the order of 1.3μs. This is 2 orders of magnitude larger than any previous implementation of spin qubits with CNT and 1 order of magnitude larger than similar device using silicon.
The proposed internship, and following PhD, aims at pushing these recent results further to demonstrate a high single-qubit gate fidelity above the fault-tolerant threshold for quantum error correction codes (and go to two-qubit gates). The strategy will rely on electrically tuning the spin qubit to further improve its coherence time (expected to be between 5μs and 25μs), boosting the spin-photon coupling with high-kinetic inductance microwave resonators and exploiting novel electron-photon coupling schemes that are currently being demonstrated in the group. The candidate will benefit from the interaction with all members of the group and of the fruitful partnership we have with the startup C12 which can then offer a CIFRE PhD funding.
The candidate should have a strong theoretical background in quantum and condensed matter physics, a strong interest in nano-devices and complex microwave techniques to manipulate a quantum system in the time domain.
Contact
Matthieu Delbecq
04/10/2024
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Thèse :
Rémunération :
121
Bringing a cold-atom interferometer to the quantum noise detection limit
Domaines
Quantum optics/Atomic physics/Laser
Quantum information theory and quantum technologies
Quantum gases
Metrology
Type de stage
Expérimental Description
Cold atom inertial sensors have many applications in fundamental physics (testing the laws of gravitation, gravitational astronomy), geosciences (measuring the Earth's gravity field or rotation) and inertial navigation. The operation of these sensors is based on atomic interferometry, taking advantage of superpositions between quantum states of different momentum in an atom, generated by optical transitions with two (or more) photons. To broaden their range of applications, it is necessary to constantly push back their performance in terms of sensitivity, stability, precision, dynamic range, compactness or robustness, ease of use and cost. The aim of this Master project will be to study and improve our state-of-the-art SYRTE's cold atom gyroscope by one order of magnitude compared with the current state of the art to reach the interferometer's detection limit, which is intrinsically linked to quantum projection noise. It will use new methods like successive joint measurements without dead time. Obtaining this regime requires some modifications to the existing experiment, in particular to the Raman lasers used to manipulate the atomic wave packet, but also to the preparation and the detection of the atomic samples. This method is very general and could also be applied to more common three-pulse interferometers such as accelerometers and gravimeters.
Contact
Arnaud Landragin
04/10/2024
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Thèse :
Rémunération :
122
Spin-photon interfaces for quantum entanglement & quantum logic operations
Domaines
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
This project aims at demonstrating new forms of spin-photon entanglement and photon-photon entanglement, and develop logic gates mediated by the spin-photon interaction, using cavity-QED devices based on semiconductor quantum dots.
Contact
Loïc Lanco
04/10/2024
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Thèse :
Rémunération :
123
Quantum computing with nuclear spins
Domaines
Condensed matter
Quantum Machines
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental Description
This project aims at developing a novel quantum computing platform, based on individual nuclear spin qubits at 10mK interfaced by superconducting quantum circuits
Contact
Patrice Bertet
03/10/2024
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Thèse :
Rémunération :
124
Single-molecule magnetic resonance spectroscopy
Domaines
Condensed matter
Biophysics
Quantum Machines
Quantum information theory and quantum technologies
Quantum optics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental Description
This project aims at performing magnetic resonance spectroscopy at the single molecule level, using superconducting quantum technologies.
Contact
Patrice Bertet
03/10/2024
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Thèse :
Rémunération :
125
Spin control of single fluorescent defects in silicon
Domaines
Condensed matter
Quantum information theory and quantum technologies
Type de stage
Expérimental Description
This project aims at investigating fluorescent point defects in silicon emitting in the near-infrared telecom bands, for the development of integrated photonic circuits for quantum technologies in silicon.
Contact
Guillaume CASSABOIS
03/10/2024
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Thèse :
Rémunération :
126
Emergent properties of altermagnets and non-collinear antiferromagnets
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
This project aims at investigating complicated magnetic textures beyond ferromagnets and antiferromagnets, for the emergence of new phenomena like orbital magnetization or anomalous Hall effect in nanomagnetic systems.
Contact
Guillaume CASSABOIS
03/10/2024
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Thèse :
Rémunération :
127
Controlling artificial atoms with light in hexagonal boron nitride
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
This project aims at investigating the photo-assisted activation of impurities in hexagonal boron nitride for the creation of artificial atoms for quantum technologies, and for classical applications where doping is required.
Contact
Guillaume CASSABOIS
03/10/2024
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Thèse :
Rémunération :
128
Superradiance of optical phonons in hexagonal boron nitride
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
While phonons are usually considered only as a dissipative reservoir, the objective of this project is to observe the luminescence of 2D optical phonons, and to study their superradiance in superlattices of boron nitride.
Contact
Guillaume CASSABOIS
03/10/2024
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Thèse :
Rémunération :
129
Quantum sensing with spin defects hosted in a two-dimensional material
Domaines
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
This project will be focused on the study of the spin and optical properties of the recently discovered boron vacancy defect in boron nitride, in order to assess its potential for quantum sensing applications, with a focus on magnetic field and electric field detection.
Contact
Guillaume CASSABOIS
03/10/2024
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Thèse :
Rémunération :
130
Lossless resilient microwave components based on disordered superconductors
Domaines
Condensed matter
Type de stage
Expérimental Description
uperconducting quantum circuits, particularly in the circuit Quantum ElectroDynamics (cQED) architecture, have achieved significant progress in recent decades. In this architecture, quantum signals are carried by microwave photons. Most cQED experiments rely on aluminum Josephson Junctions (JJ's), which act as non-linear inductors. This non-linearity enabled the development of crucial non-linear lossless microwave components, such as tunable resonators and low-noise amplifiers, essential for cQED. However, aluminum JJ-based components are limited to low magnetic fields (≲250mT), low temperatures (≲250mK), and frequencies (≲10 GHz), constraining their applications.
Using disordered superconductors with a larger superconducting gap, like NbN, could expand these limits by an order of magnitude. This project aims to demonstrate that NbN’s non-linearity can replace Al JJ’s, enabling lossless microwave components for research at higher magnetic fields (~6 T), temperatures (~4 K), and frequencies (~100 GHz).
During this master’s project, you’ll work with a team of 30, including 15 Ph.D. researchers, contributing to sample development, design, theory, and nano-fabrication in our cleanroom. You'll also learn cryogenic cooling and perform advanced DC and RF measurements. This project may evolve into a Ph.D. thesis.
References:
[1] Appl. Phys. Lett. 92, 203501, 2008
[2] Appl. Phys. Lett. 118, 142601, 2021
[3] Appl. Phys. Lett. 118, 054001, 2021
Contact
Xavier Jehl
03/10/2024
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Thèse :
Rémunération :
131
Hybrid superconductor-semiconductor for parity protected qubit
Domaines
Condensed matter
Type de stage
Expérimental Description
Hybrid Superconductor-Semiconductor (S-Sm) nanostructures are nano-circuits combining superconducting and semiconducting materials. These devices leverage superconductivity, a macroscopic quantum effect providing quantum coherence for qubits, and semiconducting properties that allow carrier control via an electrostatic gate, like in a field-effect transistor (FET). Our research focuses on aluminum-germanium nanostructures fabricated in our cleanroom. Our samples feature a loop with two hybrid nanostructures, and we observed that only even-numbered Cooper pair transport occurs, a key property for parity-protected qubits.
The project aims to integrate our hybrid nanostructure into a circuit Quantum ElectroDynamics (cQED) architecture, commonly used in superconducting quantum information. Partnering with CEA-LETI, we utilize advanced flip-chip integration to couple different quantum chips. The final samples will be tested at cryogenic temperatures using advanced DC and microwave setups.
As part of the master’s project, you’ll work with a team of 30, including 15 Ph.D. researchers, contributing to sample development, design, theory, and nano-fabrication. You'll also learn cryogenic cooling and advanced DC and RF measurements. This project may evolve into a Ph.D. thesis.
[1] Phys. Rev. Research 6, 033281, 2024
[2] arXiv:2405.14695, 2024
[3] npj Quantum Information, 6, 2020
Contact
Xavier Jehl
03/10/2024
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Thèse :
Rémunération :
132
Flying Qubit in Graphene
Domaines
Condensed matter
Quantum information theory and quantum technologies
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
The solid-state systems, presently considered for quantum computation, are built from localized two-level systems, prime examples are superconducting qubits or semiconducting quantum dots. Due to the fact that they are localized, they require a fixed amount of hardware per qubit.
Propagating or “flying” qubits have distinct advantages with respect to localised ones: the hardware footprint depends only on the gates and the qubits themselves (photons) can be created on demand making these systems easily scalable.
A qubit that would combine the advantages of localised two-level systems and flying qubits would provide a paradigm shift in quantum technology. In the long term, the availability of these objects would unlock the possibility to build a universal quantum computer that combines a small, fixed hardware footprint and an arbitrarily large number of qubits with long-range interactions. A promising approach in this direction is to use electrons rather than photons to realise such flying qubits. The advantage of electronic excitations is the Coulomb interaction, which allows the implementation of a two-qubit gate .
The aim of the present internship will be the development of the first quantum-nanoelectronic platform for the creation, manipulation and detection of flying electrons on time scales down to the picosecond and to exploit them for quantum technologies. In particular, the student will characterize a Graphene optical-to-electrical converter.
Contact
Preden Roulleau
03/10/2024
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Thèse :
Rémunération :
133
Magic Angle Twisted Trilayer Graphene
Domaines
Condensed matter
Quantum information theory and quantum technologies
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
Condensed matter physicists used to associate new exotic properties to new materials development. In 2018 a paradigm shift happened with the observation of superconductivity in two layers of graphene with a relative crystallographic rotation of ~ 1.1 degrees, the so-called magic angle twisted graphene (MATG). This unprecedented new knob to change properties of 2D materials is already showing a plethora of unexplored properties and leading to a universe of new technologicaal applications in the new and fast growing field of twistronics (Twistronics: control of the electronic properties of 2D materials in a van der Waals heterostructure by changing their relative crystallographic alignment)
The unexpected behavior in MATG is due to the existence of flat bands in its electronic band structure. These flat bands are the product of the interplay of interlayer tunneling and angle-induced momentum mismatch, which guarantees a large density of states and therefore an amplification of the effects of interactions. This causes correlated states which manifest experimentally by the emergence of new ground states such as superconductivity (SC), Mott insulators and quantum anomalous Hall effect (QAHE). Recently, we managed to observe superconductivity in a magic angle twisted trilayer graphene. In this internship, the student will perform electronic transport measurements (current and shot noise) in this device to reveal fundamental properties of cooper pairs.
Contact
Preden Roulleau
03/10/2024
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Thèse :
Rémunération :
134
Energy harvesting using topological quantum materials in the THz regime
Domaines
Condensed matter
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Today, the need of low-consumption and eco-friendly technologies has become crucial. This internship offers to study and optimize the recycling of a THz radiation into a DC current. This investigation relies on a recently discovered Hall effect – the nonlinear Hall effect – that appears in certain quantum materials. It refers to the emergence of a transverse DC current under an AC excitation, without the need of external power supply. The nonlinear Hall effect triggered by a THz radiation relies on fundamental quantum phenomena such as topology and chirality that we propose to investigate.
Contact
Louis-Anne De Vaulchier
02/10/2024
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Thèse :
Rémunération :
135
The birth of ferroelectric topological insulators
Domaines
Condensed matter
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
In the present internship, we will focus on the intriguing interplay between topology and ferroelectricity. From a fundamental point of view, combining ferroelectricity with topology is predicted to host Weyl fermions. These relativistic fermions can be mimicked by massless electrons that possess a definite chirality, meaning that their spins are parallel or antiparallel to their momenta. They are at the heart of a large number of outstanding properties that are just starting to be addressed, such as dissipationless chiral currents driven by the chiral magnetic effect, efficient spin-charge conversion due to the large anomalous Hall effect or efficient higher harmonic generation due to ultrafast dynamics. Weyl fermions are also promising particles to form qubits based on chirality. Therefore, it is of great interest to establish a platform capable of control and manipulation of Weyl fermions.
Contact
Louis-Anne De Vaulchier
02/10/2024
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Thèse :
Rémunération :
136
Josephson physics of high-transparency quantum conduction channels in 2D Germanium
Domaines
Condensed matter
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Two-dimensional (2D) Ge-based heterostructures have recently been put to the forefront of quantum technologies for their high mobility and as a platform for spin qubit architectures. Additionally, 2D-Ge forms high transparency contacts to superconductors (S), offering a promising platform for hybrid superconductor / semiconductor physics. This could have promising applications for combining superconducting with spin-based qubits.
In short S-Ge-S junction, the Josephson effect (dissipationless current flow) can be realized. Electronic transport is governed by only few conduction channels with conductance G=tau G_Q, where G_Q=2e^2/h is the quantum of conductance and 0 <tau < 1 is the channel transmission. In the superconducting state, each channel leads to a so-called Andreev bound state (ABS), which carries the supercurrent. In ballistic junctions with tau approaching 1, the ABSs can have intriguing properties which are the object of this project.
In this Master project you will fabricate and investigate 2D-Ge Josephson junctions based on new superconducting materials which form contacts to Ge with tau approaching 1. The next step consists in moving to 3- and 4-terminal Josephson junctions in 2D-Ge. Here, the ABS are more complex and can be varied by the quantum phases in each superconducting lead, which can lead to topologically distinct ground states. You will study the dc transport properties of multi-terminal junctions and confront the results to theory.
Contact
Xavier Jehl
02/10/2024
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Thèse :
Rémunération :
137
Probing the band structure of graphene-based topological 2D materials with quasiparticle interference.
Domaines
Condensed matter
Low dimension physics
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Conducting electrons screen defects by forming an oscillation of local density of states around them. This effect known as quasiparticle interferences (QPI) can be observed in the real space with the scanning tunneling microscope (STM) and is precious to determine the Fermi surface of materials which can be reconstructed from their Fourier transform.
We have recently shown that graphene’s Berry phase can also be measured from the QPI signal [1,2]. This opens new possibilities to use quasiparticle interference to determine the topological properties of materials, which are difficult to measure by other means. The present research project aims at developing the technique and apply it to new graphene based materials like twisted bilayer graphene, superconducting graphene (induced by proximity), Rhombohedral graphene etc. The success will rely on the mastering of creating defects at the surface of graphene either by ion bombardment or hydrogen functionalization. We are looking for a motivated Phd candidate with a strong background in condensed matter physics interested in low temperature scanning tunneling microscopy. The candidate will be involved in the project from sample preparation to the STM measurements and participate to a long term collaboration with Madrid University. The experimental work will be backed by theoretical input from the University of Bordeaux and Cergy Pontoise.
[1] C. Dutreix et al. Nature 574, 219 (2019)
[2] Y. Guan et al. ArXiv:2307.10024 (2023)
Contact
Vincent RENARD
02/10/2024
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Thèse :
Rémunération :
138
Graphene nanostructuring for energy conversion at nanoscale
Domaines
Condensed matter
Low dimension physics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Research on new thermoelectric (TE) devices and materials for thermal management at nanoscale is highly demanded in nanoelectronics. Energy conversion of TE nanogenerators aims to recover waste heat in nanoelectronics, improving device performances. Active TE materials must have low thermal conductivity and high electrical conductivity, which is an antonymic behavior in common bulk materials but it can be achieved in nanostructured systems. The discovery of 2D materials has open new routes of investigation in this domain.
The internship focuses on the experimental investigation of the electric, thermoelectric and thermal properties of devices based on nanostructured graphene, allowing to engineer new TE low dimensional materials and also to investigate fundamental properties relative to phonon and electron transport. Nanostructuring will be engineered by a network of holes in the few hundreds of nm range, aiming to control separately the phonon and electron mean free paths. The student will be involved in sample fabrication in clean room and electrical measurements. The team has recently demonstrated the ability of achieving a complete thermoelectrical characterization of 2D materials-based devices and has already achieved promising preliminary results. The team’s expertise in charge ransport in 2D materials and in clean room nano fabrication will be exploited in the project.
Contact
Maria Luisa Della Rocca
01/10/2024
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Thèse :
Rémunération :
139
Investigation of sub-Kelvin behaviour of advanced SiGe heterojunction bipolar transistors for quantum bits experiments
Domaines
Condensed matter
Quantum Machines
Quantum information theory and quantum technologies
Type de stage
Expérimental Description
Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) achieve the best performances of Si-based technologies and are now enabling low-noise and high-speed applications in our daily life. They rely on a graded content of Ge introduced in the epitaxial growth of the HBT base. By doing so, a true bandgap engineering is achieved and allows to optimize the transistor characteristics far beyond the limits of pure materials like Si.
Our laboratory in PHELIQS at CEA-Grenoble studies spin quantum bits made with Si MOSFETs from CEA-Leti or homemade Ge heterostructures. Even though it is not always widely known, all such qubits experiments include a HEMT or a SiGe HBT in the first front-end cryogenic low noise amplifier (LNA) of the readout chain. Recently we have designed and fabricated our own LNAs, using a commercially available BiCMOS technology, which exhibits low performances than more recent technologies.
In this internship we will investigate advanced BiCMOS devices from the B55 technology of STMicroelectronics, for applications in quantum bits experiments. We will measure their characteristics down to 3.2K or 0.45K in homemade pulse-tube based cryostats.
This work will be carried in close collaboration with STMicroelectronics which not only provides advanced BiCMOS chips but also shares its deep knowledge of SiGe HBT devices, including previous cryogenic characterizations at high frequency and above 4K.
Contact
Xavier Jehl
01/10/2024
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Thèse :
Rémunération :
140
Unveil thermoelectric properties of 2D α-In2Se3
Domaines
Condensed matter
Low dimension physics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Recently bidimensional (2D) van der Waals (vdW) III−VI semiconductors have drawn intense attention due to their unique electronic properties. Among these materials, In2Se3 in its most studied α phase, shows a great potential for a wide variety of applications in electronics, photonics and even thermoelectricity, due to its good mobility, excellent photoresponsivity, exotic ferroelectricity, and unique band structure.
First-principles calculations based on the density functional theory and Boltzmann transport theory show that monolayered α-In2Se3 is also a great candidate for high-performance thermoelectric materials with the power factor PF and the figure of merit ZT as high as 0.02W/mK2 and 2.18 at room temperature4.
The main goal of the internship is to go a step forward in the investigation of the correlation between thermoelectric and ferroelectric properties of α-In2Se3 thin layer. The student will fabricate α-In2Se3 based transistors for electric and thermoelectric investigation. The activity will cover sample fabrication in clean room (dry transfer of the 2D material, e-beam lithography, etching, metal deposition, AFM/Raman analysis …) and electrical measurements in a multi-probe station as a function of the temperature. The team has a strong expertise in the investigation of charge and spin transport in 2D materials and in clean room micro and nano fabrication techniques. This expertise will be exploited in the project.
Contact
Maria Luisa Della Rocca
01/10/2024
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Thèse :
Rémunération :
141
Crystallization of nanomaterials: theory and simulation
Domaines
Condensed matter
Statistical physics
Soft matter
Physics of liquids
Nonequilibrium statistical physics
Non-equilibrium Statistical Physics
Kinetic theory ; Diffusion ; Long-range interacting systems
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
Research overview
The formation of a crystal is triggered by the emergence of a nucleation core. Classical nucleation theory (CNT) is widely employed to discuss its nature and its origin. In CNT, the thermodynamically stable phase is always the one that grows first and its size is then driven by the free energy competition between how much it costs to build a liquid-crystal interface and the gain from growing the crystal. Yet, following Ostwald’s rule, another structure may emerge beforehand if it is closer in free energy to the mother phase. Then, structural and also chemical reorganizations happen during the growth. This multi-stage nucleation mechanism already appears in bulk systems but can be amplified in nanocrystal nucleation where surface effects and chemical reactivity are enhanced. For nanoscience to be inspired by the practical applications instead of still being driven by the synthesis possibilities, it is crucial to reach a better understanding of the unique crystallization mechanisms leading to nanocrystals.
Simulation project
Atomistic simulations will be performed to study crystallization of binary particles. Examples will be taken from well-studied materials including CuZr, NiAl, NaCl, Water... We will investigate the correlation between the thermodynamic conditions and the final nanoparticles. The goal is to ultimately better understand how nucleation theory is affected by downsizing to the nanometric scale.
Contact
Julien LAM
01/10/2024
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Thèse :
Rémunération :
142
Machine-learning approaches to model interatomic interactions
Domaines
Condensed matter
Statistical physics
Soft matter
Physics of liquids
Nonequilibrium statistical physics
Non-equilibrium Statistical Physics
Kinetic theory ; Diffusion ; Long-range interacting systems
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
Research overview
Materials can be studied using computer simulation which enables one to probe the motion of each constituent atoms and to build correlations between the macroscopic properties and the microscopic behaviors. On the one hand, traditional quantum mechanics methods provides particularly accurate results up to the electronic structure of the material. Yet, the drawback of this method concerns its computational cost which prevents from studying large system sizes and long time scales. On the other hand, effective potentials have been developed to mimic atomic interactions thereby reducing those issues. However, these potentials are often built to reproduce bulk properties of the materials and can hardly be employed to study some specific systems including interfaces and nanomaterials. In this context, a new class of interatomic potentials based on machine-learning algorithms is being developed to retain the accuracy of traditional quantum mechanics methods while being able to run simulations with larger system sizes and longer time scales.
Simulation project
Using computer simulations, the student will construct a database that should be representative of the different interactions occurring in a specific material. Machine-learning potentials based on the least-angle regression algorithm as well as neural network potentials will be trained and their accuracy will be studied as a function of the size and the complexity of the database.
Contact
Julien LAM
01/10/2024
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Thèse :
Rémunération :
143
COUPLED ELECTRON AND PHONON DYNAMICS IN GRAPHITE FOR POTENTIAL THERMOELECTRIC APPLICATIONS: EXTERNAL PHONON BATH EFFECTS
Domaines
Condensed matter
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Théorique, numérique Description
This theoretical project aims at opening new ways to improve the thermoelectric efficiency of materials, by exploring the phonon drag effect, which arises from the momentum transfer (or drag) between the out-of-equilibrium phonon and electron populations, and which is responsible for the strong increase in Seebeck and Peltier coefficients of thermoelectric materials at low temperature. The concept we aim to explore is the use of substrate as an external phonon bath to provide additional out-of-equilibrium phonons, in order to enhance phonon drag effect and shift it to higher temperatures in the conducting channel. We aim to describe the coupled dynamics of electrons and phonons via an approach based on Density Functional Theory and on the solution of coupled Boltzmann transport equations for electrons and phonons which was recently developed in our group, and to extend it by including the effect of interface and substrate.
The study will first focus on phonon drag in graphite, in link with our new collaboration with experimentalists in the framework of ANR project DragHunt.
A successful internship can be followed by a PhD on related subject, financed by ANR DragHunt.
Contact
Jelena Sjakste
01/10/2024
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Thèse :
Rémunération :
144
Coherent processes in matter waves with engineered symmetries and interactions
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Low dimension physics
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Quantum gases
Type de stage
Expérimental et théorique Description
This Master 2 internship proposal focuses on coherent processes in matter waves with engineered symmetries and interactions, exploring the quantum effects that challenge classical diffusive behaviors. Classical particles in chaotic systems experience diffusion and ergodicity, but in the quantum realm, interference can lead to phenomena like localization, breaking this diffusion. Coherent forward and backward scattering, influenced by system symmetries, is a key aspect of this. Additionally, understanding how localization and ergodicity evolve in many-body systems with interactions is an area of active research.
The Cold Atoms team at LCAR in Toulouse studies quantum chaos experimentally, using rubidium atoms in optical lattice traps. They previously observed chaos-assisted dynamical tunneling and recently measured coherent scattering peaks with matter waves. This internship will develop new engineered dynamics using cold atoms to further investigate the role of symmetries and interactions in chaotic dynamics. The candidate will use numerical models and experimental setups, including engineered symmetries in synthetic lattices and the study of interactions in tunneling dynamics.
Besides the actual experimental setup currently used, a new (quite advanced) experimental setup is being developed to explore many-body quantum chaos with enhanced stability, optical access, and control over optical potentials I the course of the PhD project following the internship.
Contact
David Guéry-Odelin
30/09/2024
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Thèse :
Rémunération :
145
Three-body interactions in coupled two-component condensates
Domaines
Quantum optics/Atomic physics/Laser
Low dimension physics
Quantum gases
Type de stage
Expérimental Description
In a context where the physics of quantum gases is usually limited to two-body interactions, we plan to study consequences of emerging three-body interactions on the dynamics of Bose-Einstein condensates.
Contact
Thomas Bourdel
27/09/2024
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Thèse :
Rémunération :
146
Random-Access Quantum Memory with Rare-Earth Ion Spins
Domaines
Condensed matter
Quantum information theory and quantum technologies
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Type de stage
Expérimental Description
A system able to store several quantum states, with the ability to absorb and retrieve a given state on demand, is dubbed a Random-Access Quantum Memory. Such memories can be used in quantum repeaters to improve long-distance quantum communication, but also to provide an alternate parallelism strategy in quantum processors. This PhD project will be about demonstrating high-fidelity storage of microwave quantum states using an ensemble of rare-earth ion spins and interfacing it with a superconducting circuit.
Our current challenge is to achieve strong, adjustable coupling between the spin and superconducting circuit—a pivotal aspect of our research. We will explore a new type of spin system that promises exceptional coherence at zero magnetic field and enhanced coupling strength. The internship will center on fabricating and measuring a test sample to evaluate the performance of this innovative system during the internship. The PhD thesis will center on developing and testing a complete hybrid quantum system able to store and retrieve quantum bits generated by a superconducting circuit into the spin ensemble.
The internship will take place in the physics lab at ENS Lyon, in the quantum circuit group (http://physinfo.fr)
Contact
Audrey Bienfait
Laboratoire : laboratoire de physique, ENS de Lyon - umr 5672
Equipe : ENS de Lyon, Physique
Site Web de l'équipe
Equipe : ENS de Lyon, Physique
Site Web de l'équipe
25/09/2024
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Thèse :
Rémunération :
147
Quantum Spintronic Qubit: first experiments
Domaines
Condensed matter
Quantum information theory and quantum technologies
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Many hardware platforms exist to implement qubit operations for quantum technologies, but these
platforms, although conceptually elegant, do not offer a straightforward path toward consumer
applications in terms of energy/resource usage (#QEI): low/very low temperatures, external magnetic
fields, lasers/microwave sources, a room-full of optical/electrical/vacuum/cryogenic equipment, difficulty
to entangle qubits... To address this challenge, we propose to utilize spintronics, and its industrial penetration as a green nanotechnology, to develop a new platform around the quantum spintronic qubit. Since this paradigm is onyl now emerging, this experimental topic will investigate the first foundational elements of this new paradigm, with inroads into quantum communication and energy harvesting.
Contact
Martin Bowen
25/09/2024
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Thèse :
Rémunération :
148
Inertial quantum sensing based on optomechanical coupling in rare-earth-doped crystals
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Quantum information theory and quantum technologies
Metrology
Type de stage
Expérimental Description
Developing a broadband, high-sensitivity accelerometer operating at cryogenic temperatures is a key challenge in many cutting-edge experimental physics domains, from quantum technologies (including near-field microscopy, quantum memories, etc.) to gravitational wave detection. To realize such a sensor, a promising approach is hybrid optomechanics, which couples quantum and mechanical degrees of freedom in a single physical system.
Rare-earth ion-doped crystals, known for their extremely narrow optical transitions at low temperature (~3K), exhibit natural optomechanical coupling through the piezospectroscopic sensitivity of the ion’s energy levels to mechanical stress. These crystals have recently emerged as strong candidates for quantum-enabled, low-temperature accelerometry, and we recently demonstrated continuous optical measurement of cryostat vibrations with such crystals, with an already promising sensitivity and bandwidth [1,2].
However, significant work is needed to obtain an ultra-sensitive, unidirectional and calibrated accelerometer.
During this internship, we will investigate the fundamental and technical limitations of the method (in terms of sensitivity and bandwidth in particular), using emulated or real vibrations. Additionally, we aim to extend the operational range to higher temperatures (up to 10K), which will be key for expanding the potential applications of our sensor
Contact
Anne Louchet-Chauvet
Laboratoire : Institut Langevin - Ondes et Images - UMR7587
Equipe : Materials, Resonances, Interfaces
Site Web de l'équipe
Equipe : Materials, Resonances, Interfaces
Site Web de l'équipe
25/09/2024
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Thèse :
Rémunération :
149
Quantum Nano-Photonics with 2D Materials
Domaines
Condensed matter
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
The 2D+ Research Group at CRHEA – located in the French Riviera (Côte d’Azur) near Nice, France – is seeking a highly motivated and talented Master’s student to join our cutting-edge research in quantum nano-photonics. This internship offers a unique opportunity to work on foundational quantum technologies, with a clear pathway to extend the project into a funded PhD position as part of the ANR project “NEAR-2D.”
-->Research Focus
The master intern’s primary objective will be coupling two quantum emitters using 2D materials like MoSe2. This initial project will serve as the foundation for further exploration of quantum emitter arrays during the PhD. By leveraging near-field interactions and quantum collective effects, this work aims to pave the way for new methods of controlling light-matter interactions at the nanoscale.
As part of the PhD, the candidate will expand this research by creating sub-λ arrays of quantum emitters and exploring quantum collective effects like sub-radiance and super-radiance, which have vast potential in nano-photonics and quantum technologies.
Contact
Antoine Reserbat-plantey
24/09/2024
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Thèse :
Rémunération :
150
Operando investigation of optoelectronic device using advanced photoemission
Domaines
Condensed matter
Low dimension physics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
The aim of this project is to go beyond standard material characterization by studying the electronic properties of devices during operation. Leveraging the unique platform developed by our group at INSP, which combines Raman, infrared, and visible spectroscopy with multi-source X-ray photoemission (XPS) across a broad energy range (from meV to 5 keV), and offering precise control of temperature and bias, we will explore the energy landscape of nanocrystal-based LEDs. These devices have a vertical geometry typically incompatible with the low escape depth of standard photoelectron spectroscopy. However, the hard X-ray capability of our setup, combined with the redesigned device architecture incorporating 2D materials, will allow us to probe the active layer under operando conditions.
Contact
Debora Pierucci
24/09/2024
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Thèse :
Rémunération :
151
Biréfringence Magnétique du Vide / Vacuum Magnetic Birefringence
Domaines
Quantum optics/Atomic physics/Laser
Non-linear optics
Metrology
Type de stage
Expérimental Description
The BMV project (Vacuum Magnetic Birefringence) is an ambitious experiment whose goal is to check in-laboratory predictions for vacuum energy in quantum electrodynamics. This theory predicts that vacuum, in the presence of a magnetic field, behaves as a birefringent medium. The experiment blends intense pulsed magnetic fields with a sensitive optical apparatus, centered around a high-finesse cavity.
Contact
Remy Battesti
24/09/2024
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Thèse :
Rémunération :
152
Light transport in optical fibers and reciprocity breaking
Domaines
Condensed matter
Statistical physics
Low dimension physics
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Kinetic theory ; Diffusion ; Long-range interacting systems
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Reciprocity in optics is often seen as a property responsible for the fact that “if I can see you, you can see me”. In multiple scattering coherent wave transport, i.e., if interferences within the scattering region are taken into account, reciprocity is known to reduce the transmission of the medium with respect to a situation where interferences are absent. This phenomenon is known as localization. It is possible to break reciprocity for instance in the
presence of materials showing some magneto-optical Faraday effect. Breaking of reciprocity gives new insight to the fundamental understanding of coherent wave transport, and therefore, we propose, in this master project, to develop an original setup to measure the influence of reciprocity in coherent wave transport in multimode optical fibers.
Contact
Geoffroy Aubry
24/09/2024
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Thèse :
Rémunération :
153
Active photonic devices using colloidal quantum dots
Domaines
Condensed matter
Low dimension physics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
The project aims to shape the light matter interaction in a nanocrystal use for infrared sensing. We aim to introduce new functionalities such as a reconfigurable photoresponse with external knob such as bias and in the long term transfer the concept to the camera level
Contact
Emmanuel Lhuillier
23/09/2024
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Thèse :
Rémunération :
154
Quantum information in quantum optics and superselection rules
Domaines
Quantum information theory and quantum technologies
Quantum optics
Metrology
Type de stage
Théorique, numérique Description
Quantum information can be encoded in the quantum electromagnetic field in various ways. For example, non-classical superpositions of photon number states, such as Schrödinger cat states, provide one form of encoding. Alternatively, the degrees of freedom of single photons, such as polarization, can be used to encode qubits. An intriguing question arises: is there a way to relate these two types of quantum information encoding—one based on particle statistical properties and the other on mode/particle entanglement? Can one be mapped onto the other while adhering to physical principles, such as energy conservation, or informational principles, such as providing the same advantage over classical encodings? Our goal is to design common quantifiers for these quantum optical encodings.
During this internship, we will address this issue in the particular field of quantum metrology, which aims to achieve quantum-enhanced precision in parameter estimation. Using single photons in different frequency modes results in the same type of precision enhancement as that achieved with photon number state superpositions. Our objective is to develop a unified formalism that describes all quantum optical encodings capable of achieving quantum-enhanced precision.
Contact
Perola Milman
12/09/2024
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Thèse :
Rémunération :
155
Thermodynamics of open quantum systems in the coherent-dissipative regime
Domaines
Low dimension physics
Quantum Machines
Non-relativistic quantum field theory, quantum optics, complex quantum systems
Nonequilibrium statistical physics
Quantum information theory and quantum technologies
Quantum optics
Non-equilibrium Statistical Physics
Type de stage
Théorique, numérique Description
The booming field of quantum thermodynamics analysis quantum signatures in work and heat flows, the performances of quantum heat engines and derive fundamental constraints on quantum dynamics. The goals of this theory project is to develop a new methodology able to explore the "coherent dissipative" regime of quantum open systems, where large deviations from classical thermodynamic behavior are expected, but which is not well captured by existing methodologies. Applications will cover quantum heat engines and different situations of experimental relevance, in connexion with experimentalists.
This Master project can be followed by a PhD funded by the ERC Starting grant project "QARNOT".
Contact
Cyril Elouard
12/09/2024
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Thèse :
Rémunération :
156
Quantum imaging for sub-shot noise monitoring of optically-levitated nano-particles
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Quantum information theory and quantum technologies
Quantum optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
In optical levitation, a nanoparticle is trapped in vacuum using tightly focused light. The light produces a force akin to a mechanical spring and the system reduces to a simple mass-spring resonator with kHz oscillations. Despite its simplicity, a levitated object provides remarkable interactions between light and its motion that can be harnessed to display quantum properties. In that regard, the particle must be cooled down to its quantum ground state, which requires to monitor its motion with optimal precision. Typically, this is achieved using the classical light produced by a laser. Yet, lasers are intrinsically shot-noise limited, thus making cooling challenging. Recently, some works have emphasized that quantum light can outperform classical light. For instance, entangled photons can serve to suppress shot noise. A photon of the pair images a target (signal), while a second acts as a reference (idler). As shot noise identically affects both photons, it is suppressed from the signal by subtracting the idler.
During this internship, the candidate will experimentally harness entangled photons to perform sub-shot noise monitoring of levitated objects. He or she will develop an entangled-photon source, later on deployed on a levitation setup. To characterize the source, the student will visit the team of Pr. Molina in San Sebastian (Spain). Following the internship, he or she will be offered a PhD in cotutelle between Prs. Bachelard and Molina’s teams.
Contact
Nicolas Bachelard
Laboratoire : Laboratoire Ondes et Matière d'Aquitaine - UMR 5798
Equipe : Nanophotonics Group
Site Web de l'équipe
Equipe : Nanophotonics Group
Site Web de l'équipe
11/09/2024
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Thèse :
Rémunération :
157
Casimir-Polder interaction control of cold atoms and nano devices for fundamental physics
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Quantum gases
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental et théorique Description
An atom in front of a surface is one of the simplest and fundamental problem in physics. Yet, it allows testing quantum electrodynamics, while providing platforms for quantum technologies. In particular, the presence of electromagnetic quantum fluctuations leads to a force between an atom and a surface. This force is called the Casimir-Polder (C-P) force. Despite its simplicity, C-P interaction, at its fundamental level, remains largely unexplored. In this context, our team has built a slow atomic beam interacting with a nanograting. This jet interacts with a carefully self-engineered nanograting, leading to a diffraction pattern dominated by the C-P force. The current interest of the experiment is to achieve an in-depth understanding of the C-P interaction. To achieve this goal, the successful applicant will take an active role in various aspects of the experiment including data acquisition, data analysis, the development of tools for characterizing the atomic source, and the installation of an optical dipole trap. Additionally, the internship has as well a theoretical component with the description of the interference figure and quantum electrodynamic calculations. The short-term goal of the project is to tailor the C-P interaction using material geometries. In the medium term, this work will open the door to study eventual modifications of the Newtonian gravitational interaction at short range, where C-P interaction shields such forces.
Contact
Quentin Bouton
11/09/2024
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Thèse :
Rémunération :
158
Terahertz Cavity Electrodynamics of Superconducting Collective Modes
Domaines
Condensed matter
Low dimension physics
Nouveaux états électroniques de la matière corrélée
Topological materials, Quantum Transport, Cavity Quantum Electrodynamics
Non-linear optics
Nanophysics, nanophotonics, 2D materials and van der Waals heterostructures,, surface physicss, new electronic states of matter
Type de stage
Expérimental Description
Strong light-matter interactions between quantum materials and the vacuum field of cavities at TeraHertz (THz) frequencies is emerging as a new frontier for the control of material properties. Among quantum materials, superconductors (SC) hold a special place and a timely question has arisen regarding the possibility to tune their spectacular properties by dressing their collective modes with THz cavity photons. In this internship, we propose to study the collective modes of NbSe2, an exotic SC exhibiting simultaneously SC and a charge density-wave (CDW) state. Of particular interest will be to investigate the dynamics of its Higgs-mode, an analogue of the Higgs-boson in SCs, and its interaction with the CDW mode. This will be achieved with a combination of equilibrium THz time-domain spectroscopy and pump-probe THz spectroscopy. The first steps towards integration of this SC inside THz cavities and the dressing of its collective modes will carried out.
Contact
Yannis LAPLACE
Laboratoire : Laboratoire des solides irradiés - UMR 7642
Equipe : New electronic states - TeraX-lab
Site Web de l'équipe
Equipe : New electronic states - TeraX-lab
Site Web de l'équipe
02/09/2024
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Thèse :
Rémunération :