Coherent multiple scattering of out-of-equilibrium interacting Bose gases

TL;DR

This paper reviews recent advances in understanding how weakly interacting disordered Bose gases exhibit mesoscopic effects like localization and coherent scattering, highlighting the impact of interactions on their out-of-equilibrium dynamics.

Contribution

It provides a comprehensive overview of experimental and theoretical progress in mesoscopic phenomena and the role of interactions in out-of-equilibrium disordered Bose gases.

Findings

Observation of mesoscopic effects such as coherent back scattering.

Analysis of how interactions induce dephasing and thermalization.

Insights into the transition to superfluidity in disordered Bose gases.

Abstract

We review recent theoretical and experimental progresses in the coherent multiple scattering of weakly interacting disordered Bose gases. These systems have allowed, in the recent years, a characterization of weak and strong localization phenomena in disorder at an unprecedented level of control. In this paper, we first discuss the main physical concepts and recent experimental achievements associated with a few emblematic "mesoscopic" effects in disorder like coherent back scattering, coherent forward scattering or mesoscopic echos, focusing on the context of out-of-equilibrium cold-atom setups. We then address the role of weak particle interactions and explain how, depending on their relative strength with respect to the disorder and on the time scales probed, they can give rise to a dephasing mechanism for weak localization, thermalize a non-equilibrium Bose gas or make it become a superfluid.