Waves and quantum physics

Wave propagation in diffusive media is an important subject for numerous fields (medical imaging, acoustics, seismology, stellar physics, etc.). The experiments that we pursue make use of an original medium: a laser-cooled atomic cloud. The peculiar properties of this diffusive medium (strong resonances, strong nonlinearity, quantum internal structure of the scatterers, mechanical effects of light on the atoms, quantum effects, etc.) give rise to a very rich physics. We study several subjects in this context.
More generally, we are interested in collective effects in light-atom interaction, which include multiple scattering of light but also nonlinear optics or cooperative scattering.
We have also studied dynamics of matter waves with a Bose-Einstein condensation experiment.
Finally, we have been involved in a fruitful collaboration with astrophysicists on the measurement of light correlations (Hanbury Brown and Twiss technique).
Our work is mainly experimental, using three cold-atom apparatus and several smaller hot-vapor setups, but also theoretical, in particular through many collaborations.

Team website

The group Waves in complex systems is interested in controlling the classical wave transport properties in various systems whose mastered designs range from homogeneous systems with complex geometries to either periodic or disordered structured materials. Thanks to experimental versatile platforms in optics and microwaves, and with a strong expertise in numerical simulations in wave chaos theory (effective Hamiltonian, random matrix theory, etc.), the group investigates various themes : mixed dynamics in multimode optical fibers, electromagnetic chaotic reverberation chambers, superfluidity and condensation of light, analog approaches of topological effects in condensed matter, wave diffusion or localization. While the undertaken studies are motivated by the incentive of addressing fundamental questions, they still give rise to numerous applicative developments.

Team website

Our team works in different themes pertaining to quantum physics and relativity, approached with analytical as well as numerical approaches. We are working on correlated quantum systems with few or many bodies, with applications to cold atoms, mesoscopic physics, Efimov physics or correlated photonic systems. Quantum field theory is another important research topic, especially quantum chromodynamics. Finally we are developing researches in relativity with applications to satellite positioning systems.

Team website