Kinetic Model of Trapped Finite Temperature Binary Condensates

TL;DR

This paper develops a comprehensive non-equilibrium model for the dynamics of two finite-temperature Bose-Einstein condensates, incorporating dissipative equations and quantum Boltzmann equations to analyze inter-component interactions and transport processes.

Contribution

It introduces a self-consistent theoretical framework combining dissipative Gross-Pitaevskii and quantum Boltzmann equations for two interacting condensates at finite temperature.

Findings

Identifies dominant inter-component scattering process near equilibrium.

Demonstrates relevance for sympathetic cooling in atomic mixtures.

Analyzes both miscible and immiscible condensate mixtures.

Abstract

We construct a fully self-consistent non-equilibrium theory for the dynamics of two interacting finite-temperature atomic Bose-Einstein condensates. The condensates are described by dissipative Gross-Pitaevskii equations, coupled to quantum Boltzmann equations for the thermal atoms. The density-density interactions between atoms in different components facilitate a number of transport processes of relevance to sympathetic cooling: in particular, identification of an inter-component scattering process associated with collisional "exchange" of condensed and thermal atoms between the components, is found numerically to dominate close to equilibrium, for both realistic miscible and immiscible trapped atomic $^{87}$Rb-$^{41}$K and $^{87}$Rb-$^{85}$Rb condensate mixtures.