Quantitative study of quasi-one-dimensional Bose gas experiments via the stochastic Gross-Pitaevskii equation

TL;DR

This paper demonstrates that the stochastic Gross-Pitaevskii equation effectively models quasi-one-dimensional Bose gas experiments, accurately matching experimental density profiles and fluctuations by combining a stochastic equation for axial modes with ideal gases for transverse excitations.

Contribution

It introduces a quasi-one-dimensional stochastic equation for axial modes and combines it with ideal Bose gases for transverse modes to improve modeling accuracy.

Findings

Accurately reproduces experimental in situ density profiles.

Matches experimental density fluctuation data.

Validates the stochastic Gross-Pitaevskii equation as a modeling tool.

Abstract

The stochastic Gross-Pitaevskii equation is shown to be an excellent model for quasi-one-dimensional Bose gas experiments, accurately reproducing the in situ density profiles recently obtained in the experiments of Trebbia et al. [Phys. Rev. Lett. 97, 250403 (2006)] and van Amerongen et al. [Phys. Rev. Lett. 100, 090402 (2008)], and the density fluctuation data reported by Armijo et al. [Phys. Rev. Lett. 105, 230402 (2010)]. To facilitate such agreement, we propose and implement a quasi-one-dimensional stochastic equation for the low-energy, axial modes, while atoms in excited transverse modes are treated as independent ideal Bose gases.