Pour trouver l'offre idéale !
Offres de stage et propositions de thèse
Critères de sélection
Nombre d'offres
19
1
Rare-earth-doped crystal spectroscopy for signal processing architectures
Domaines
Quantum optics/Atomic physics/Laser
Condensed matter
Quantum information theory and quantum technologies
Type de stage
Expérimental Description
Rare-earth ion-doped crystals exhibit exceptionally narrow optical transitions at low temperatures (around 3K). These unique properties make them ideal for foundational quantum technology applications, including quantum memories, quantum sensors, and quantum-enabled signal processing architectures. Over the past decades, our team, in a long-standing collaboration with Thales Research & Technology and IRCP, has developed a number of state-of-the-art signal processing designs, including a spectral analyzer demonstrator at the industrial level and an agile photonic filter. Nevertheless, the development of cutting-edge architectures goes hand-in-hand with ongoing exploration of alternative materials, always with specific applications in mind. With this internship, we want to continue our exploration focusing on Tm:YGG and Er:YSO, in the perspective of optimizing our spectrum analyzer designs.
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
13/11/2024
/
Thèse :
Rémunération :
2
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
/
Thèse :
Rémunération :
3
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
/
Thèse :
Rémunération :
4
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
/
Thèse :
Rémunération :
5
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
/
Thèse :
Rémunération :
6
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 :
7
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 :
8
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 :
9
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 :
10
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 :
11
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
/
Thèse :
Rémunération :
12
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
/
Thèse :
Rémunération :
13
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
/
Thèse :
Rémunération :
14
Energy-space sub-diffusion in driven disordered Bose gases
Domaines
Non-equilibrium Statistical Physics
Kinetic theory ; Diffusion ; Long-range interacting systems
Quantum gases
Type de stage
Théorique, numérique Description
During this M2 internship, we propose to study theoretically and numerically the dynamics of Bose gases subjected to both an oscillating driving force and a spatially disordered potential. This scenario, recently realized experimentally, gives rise to an original mechanism of sub-diffusion in energy space, whose quantitative description for realistic models of disorder remains to establish. This is the task that will be accomplished during this internship. More generally, this internship will be an opportunity to become familiar with the modern research fields of non-equilibrium quantum physics and ultracold Bose gases.
Contact
Nicolas Cherroret
05/10/2024
/
Thèse :
Rémunération :
15
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
/
Thèse :
Rémunération :
16
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
/
Thèse :
Rémunération :
17
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
/
Thèse :
Rémunération :
18
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
/
Thèse :
Rémunération :
19
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
/
Thèse :
Rémunération :