Finite temperature correlations in the Lieb-Liniger 1D Bose gas

TL;DR

This paper develops a Bethe Ansatz-based method to accurately compute finite-temperature response functions of the Lieb-Liniger 1D Bose gas, revealing how thermal fluctuations influence critical behavior in experimentally relevant regimes.

Contribution

The authors introduce a novel Bethe Ansatz approach for calculating finite-temperature dynamical correlations in the Lieb-Liniger model, applicable across various parameters.

Findings

Thermal fluctuations smooth zero-temperature critical behavior.

Explicit quantitative results for experimentally accessible regimes.

Method enables accurate evaluation over broad momentum, frequency, and temperature ranges.

Abstract

We address the problem of calculating finite-temperature response functions of an experimentally relevant low-dimensional strongly-correlated system: the integrable 1D Bose gas with repulsive \delta-function interaction (Lieb-Liniger model). Focusing on the observable dynamical density-density function, we present a Bethe Ansatz-based method allowing for its accurate evaluation over a broad range of momenta, frequencies, temperatures and interaction parameters, in finite but large systems. We show how thermal fluctuations smoothen the zero temperature critical behavior and present explicit quantitative results in experimentally accessible regimes.