Domaines
Condensed matter
Type of internship
Expérimental Description
In computers magnetism intervenes in the data storage components, with information coded by the magnetization direction of submicronic magnetic domains. The calculations are instead done using semiconducting materials, with transistors performing logical operations (“NOT”, “AND” etc.). A whole new paradigm proposes to use magnetic materials to perform these operations, by encoding the information on the amplitude and phase of so-called “spin-waves”, magnetic excitations. They can be excited by RF antennas, or more recently by surface acoustic waves, thanks to magneto-elasticity (an effect coupling magnetization and strain ). Foreseen advantages are a higher integrability, a higher tunability and even a lower consumption of devices for our increasingly energy-greedy digital world.
Most groups detect these spin waves electrically, after propagation along a wave-guide, or a delay line. While these measurements are ideal for a commercial device, they do not provide information about the physics at play between the excitation and detection of the waves. The aim of this internship will therefore be to improve an existing set-up capable of synchronizing an RF excitation with short laser pulses probing the magnetization dynamics induced by the resulting GHz RF field or strain wave. The challenge will be to improve the signal to noise ratio, and increase the maximum (minimum) spin wave detectable frequency (wave-length).
Contact
Laura Thevenard