Critical Temperature of a Trapped Bose Gas: Mean-Field Theory and Fluctuations

TL;DR

This paper explores how mean-field effects and fluctuations influence the critical temperature of a trapped Bose gas, proposing an adiabatic ramping method to distinguish these effects experimentally, revealing fluctuation impacts at higher frequencies.

Contribution

It introduces an adiabatic cooling scheme to differentiate mean-field and fluctuation effects on Bose-Einstein condensation in trapped gases.

Findings

Fluctuation effects can induce Bose condensation at higher trap frequencies than mean-field predictions.

The proposed method enhances the detectability of fluctuation effects in experiments.

Mean-field and fluctuation contributions to the critical temperature can be distinguished through adiabatic ramping.

Abstract

We investigate the possibilities of distinguishing the mean-field and fluctuation effects on the critical temperature of a trapped Bose gas with repulsive interatomic interactions. Since in a direct measurement of the critical temperature as a function of the number of trapped atoms these effects are small compared to the ideal gas results, we propose to observe Bose-Einstein condensation by adiabatically ramping down the trapping frequency. Moreover, analyzing this adiabatic cooling scheme, we show that fluctuation effects can lead to the formation of a Bose condensate at frequencies which are much larger than those predicted by the mean-field theory.