Artur Widera
Ultracold gases have proven powerful model systems to study quantum dynamics in various scenarios. In particular, the ability to tune atomic interactions and to interface these systems with time-dependent potentials opens the door to probe fascinating nonequilibrium dynamics experimentally.
Here, I will discuss our experiments investigating an ultracold Fermi gas along the BEC-BCS crossover in time-dependent disorder.
First, we study the response of a molecular Bose-Einstein condensate when quenched into and out of a disordered optical potential. We unravel the in-situ density and the global phase response and find markedly different time scales. Tracing the quantum relaxation following a quench out of a disordered system, we find that the quantum phase needs a surprisingly long time to relax, pointing at possibly long-lived phase excitations.
Second, we investigate the dissipative dynamics of an interacting gas in disorder with tunable correlation time, where we probe the emerging excitations and dynamics. Comparing the dynamics of thermal and quantum gases, we conclude that the quantum gas is only affected via thermal coupling to the non-condensed part for a broad range of correlation times.