Dynamics of Homogeneous Bose Gases

Quantum gases are an ideal platform to investigate out-of-equilibrium processes in real time. Using a 3D homogenous Bose gas with tunable interactions, we study effects ranging from density waves in linear response, via purely non-linear damping of the fundamental mode, to far-from-equilibrium processes in strongly driven and quenched systems. In particular, we present our microscopic study of the first and second sound mode in a weakly driven superfluid at finite temperatures and our observation of third-harmonic generation for a strong drive of the fundamental BEC mode. For a longer drive, a turbulent cascade emerges with a universal power-law distribution in quasi-steady-state. Finally, we demonstrate self-similar scaling in space-time by strongly quenching the systems through the BEC transition.