Canonical c-field approach to interacting Bose gases: stochastic interference of matter waves

TL;DR

This paper introduces a stochastic c-field equation for interacting Bose gases that accurately models equilibrium and non-equilibrium dynamics, enabling efficient simulations of interference patterns in ultracold atomic experiments.

Contribution

The authors develop a canonical c-field approach based on a stochastic differential equation that incorporates fixed particle number, improving numerical efficiency and agreement with experimental data.

Findings

Successfully reproduces interference patterns in quasi-1D Bose gases.

Accurately predicts statistical properties like contrast distributions.

Demonstrates the method's applicability to both equilibrium and non-equilibrium scenarios.

Abstract

We present a stochastic matter field equation for an interacting many-body Bose system in equilibrium at ultracold finite temperature. Moreover, the proposed equation can be used for non-equilibrium dynamics on phenomenological grounds. This stochastic differential equation is based on a field phase space representation reflecting the underlying canonical density operator (fixed particle number N). Remarkably, it allows for an efficient numerical implementation. We apply our canonical c-field method to interference experiments with quasi-one dimensional Bose gases. Crucial features of these interference patterns are reproduced very well and also statistical properties in terms of distributions, e.g. for the contrasts, agree well with experimental results.