Efficient numerical description of the dynamics of interacting multispecies quantum gases

Abstract

We present a highly efficient method for the numerical solution of coupled Gross–Pitaevskii equations describing the evolution dynamics of a multi-species mixture of Bose–Einstein condensates in time-dependent potentials. This method, based on a moving and expanding reference frame, compares favorably to a more standard but much more computationally expensive solution based on a frozen frame. It allows an accurate description of the long-time behavior of interacting, multi-species quantum mixtures including the challenging problem of long free expansions relevant to microgravity and space experiments. We demonstrate a successful comparison to experimental measurements of a binary Rb–K mixture recently performed with the payload of a sounding rocket experiment.