Thermal suppression of demixing dynamics in a binary condensate

Abstract

We investigate the demixing dynamics in a binary two-dimensional (2D) Bose superfluid using classical-field dynamics. By quenching the interspecies interaction parameter, we identify a strong and weak separation regime depending on the system temperature and the quench parameter. In the strong separation regime our results are in agreement with the inertial hydrodynamic domain growth law of binary fluids and a Porod scaling law for the structure factor at zero temperature is found. In the weak separation regime thermal fluctuations modify both the domain growth law and the Porod tail of the structure factor. Near the superfluid transition temperature the scaling dynamics approaches the diffusive growth law of a 2D conserved field. We then analyze the demixing dynamics in a box cloud. For low quench we find distinctive domain dynamics dictated by the boundary condition. Otherwise, the dynamics are qualitatively similar to those of systems with periodic boundary conditions.