Equilibration of a finite temperature binary Bose gas formed by population transfer

TL;DR

This paper investigates how a binary Bose gas reaches equilibrium after an instantaneous population transfer between species, revealing the effects of interactions on condensate fractions through classical field simulations.

Contribution

It introduces a detailed analysis of the dynamics and equilibrium states of a binary Bose gas following population transfer, highlighting the role of interspecies interactions.

Findings

Condensate fractions can remain unaffected or be significantly reduced depending on interaction regimes.

In immiscible regimes, one or both condensates are drastically diminished at equilibrium.

The study maps out the dependence of final states on population transfer and interspecies interactions.

Abstract

We consider an equilibrium single-species homogeneous Bose gas from which a proportion of the atoms are instantaneously and coherently transferred to a second species, thereby forming a binary Bose gas in a non-equilibrium initial state. We study the ensuing evolution towards a new equilibrium, mapping the dynamics and final equilibrium state out as a function of the population transfer and the interspecies interactions by means of classical field methods. While in certain regimes, the condensate fractions are largely unaffected by the population transfer process, in others, particularly for immiscible interactions, one or both condensate fractions are vastly reduced to a new equilibrium value.