Relative phase fluctuations of two coupled one-dimensional condensates

TL;DR

This paper investigates how thermal fluctuations and coupling strength influence the relative phase fluctuations and correlation length between two coupled one-dimensional condensates at thermal equilibrium.

Contribution

It provides a detailed analysis of the interplay between thermal excitations and coupling in determining phase coherence in coupled 1D condensates.

Findings

Relative phase fluctuations depend on temperature and coupling strength.

Correlation length varies with thermal and coupling parameters.

Coupling suppresses phase fluctuations at low temperatures.

Abstract

We study the relative phase fluctuations of two one-dimensional condensates coupled along their whole extension with a local single-atom interaction. The thermal equilibrium is defined by the competition between independent longitudinal thermally excited phase fluctuations and the coupling between the condensates which locally favors identical phase. We compute the relative phase fluctuations and their correlation length as a function of the temperature and the strength of the coupling.