Yang-Yang thermometry and momentum distribution of a trapped one-dimensional Bose gas

TL;DR

This paper introduces a method for precise temperature measurement of a one-dimensional Bose gas using Yang-Yang solutions and validates it with stochastic Gross-Pitaevskii simulations, matching experimental data.

Contribution

It presents the first quantitative comparison of Yang-Yang thermometry with stochastic Gross-Pitaevskii theory for a trapped 1D Bose gas.

Findings

Yang-Yang thermometry accurately determines temperature from momentum distribution.

Stochastic Gross-Pitaevskii theory agrees with Yang-Yang thermometry.

Validated temperature measurements match experimental results.

Abstract

We describe the use of the exact Yang-Yang solutions for the one-dimensional Bose gas to enable accurate kinetic-energy thermometry based on the root-mean-square width of an experimentally measured momentum distribution. Furthermore, we use the stochastic projected Gross-Pitaevskii theory to provide the first quantitative description of the full momentum distribution measurements of Van Amerongen et al., Phys. Rev. Lett. 100, 090402 (2008). We find the fitted temperatures from the stochastic projected Gross-Pitaevskii approach are in excellent agreement with those determined by Yang-Yang kinetic-energy thermometry.