Condensate Formation in a Bose Gas

TL;DR

This paper explores the formation of Bose-Einstein condensates in dilute atomic hydrogen, highlighting the role of collision dynamics and phase transition proximity in achieving condensation within the gas's lifetime.

Contribution

It demonstrates that rapid condensate nucleation is possible if the gas is quenched into the critical region, and clarifies the impact of elastic collisions on condensate formation.

Findings

Condensate nucleation time is on the order of ar(ar{ abla}( abla)k_{B}T_{c})

Elastic collisions facilitate rapid thermalization, enabling BEC formation within the gas lifetime

In doubly-polarized hydrogen, inelastic decay processes are less frequent, supporting BEC achievement

Abstract

Using magnetically trapped atomic hydrogen as an example, we investigate the prospects of achieving Bose-Einstein condensation in a dilute Bose gas. We show that, if the gas is quenched sufficiently far into the critical region of the phase transition, the typical time scale for the nucleation of the condensate density is short and of $O(\hbar/k_{B}T_{c})$. As a result we find that thermalizing elastic collisions act as a bottleneck for the formation of the condensate. In the case of doubly-polarized atomic hydrogen these occur much more frequently than the inelastic collisions leading to decay and we are lead to the conclusion that Bose-Einstein condensation can indeed be achieved within the lifetime of the gas.