We investigate an ultra-cold mixture of Bose gases interacting via spin-changing collisions by studying the dynamics of spin fluctuations. The experimental implementation employs 23Na and 7Li atoms, which are prepared out of equilibrium across a wide range of initial conditions. We identify three regimes in the dynamics of the system for different initial states: a long-lived metastable regime, an instability range with strong growth of fluctuations, and a fast relaxing regime approaching thermal equilibrium. Theoretical modelling of the data allows us to reconstruct effective potentials which characterize the different dynamical regimes of the system.

A. Hegde, R. Ott, A. Xia, V. Kasper, J. Berges, F. Jendrzejewski, “Non-equilibrium dynamics of fluctuations in an ultra-cold atomic mixture”, arXiv:2204.06456 (2022).


Related to Project B04