Phase coherence in quasicondensate experiments: an ab initio analysis via the stochastic Gross-Pitaevskii equation

TL;DR

This paper uses an ab initio stochastic Gross-Pitaevskii equation approach to analyze the temperature dependence of phase coherence in quasi-one-dimensional Bose gases, achieving excellent agreement with experimental data.

Contribution

It introduces a self-consistent modification of the stochastic Gross-Pitaevskii equation to accurately model transverse effects in quasi-1D Bose gases, providing a new method to identify phase coherence temperature.

Findings

Excellent agreement with experimental phase coherence data

Validated a new phase temperature identification method

Demonstrated the model's applicability in the regime μ ~ few ħω_⊥

Abstract

We perform an ab initio analysis of the temperature dependence of the phase coherence length of finite temperature, quasi-one-dimensional Bose gases measured in the experiments of Richard et al. (Phys. Rev. Lett. 91, 010405 (2003)) and Hugbart et al. (Eur. Phys. J. D 35, 155-163 (2005)), finding very good agreement across the entire observed temperature range ($0.8<T/T_{\phi}<28$). Our analysis is based on the one-dimensional stochastic Gross-Pitaevskii equation, modified to self-consistently account for transverse, quasi-one-dimensional effects, thus making it a valid model in the regime $\mu ~ few \hbar \omega_\perp$. We also numerically implement an alternative identification of $T_{\phi}$, based on direct analysis of the distribution of phases in a stochastic treatment.