Quantum Monte Carlo study of the 3D-1D crossover for a trapped Bose gas

TL;DR

This paper uses Quantum Monte Carlo methods to study the transition of a trapped Bose gas from three to one dimension, revealing significant beyond mean-field effects and Fermi-like behavior in the Tonks gas regime.

Contribution

It provides exact quantum Monte Carlo results for the 3D-1D crossover in a Bose gas, comparing them with mean-field and Lieb-Liniger predictions, and highlights beyond mean-field phenomena.

Findings

Identification of beyond mean-field effects

Observation of Fermi-like properties in the Tonks regime

Quantitative comparison with mean-field and Lieb-Liniger models

Abstract

We investigate the cross-over from three to one dimension in a Bose gas confined in highly anisotropic traps. By using Quantum Monte-Carlo techniques, we solve the many-body Schrodinger equation for the ground state and obtain exact results for the energy per particle and the mean square radii of the cloud in the transverse and longitudinal direction. Results are compared with the predictions of mean-field theory obtained from the Gross-Pitaevskii equation and with the 1D Lieb-Liniger equation of state. We explicitly prove the occurrence of important beyond mean-field effects, including the appearance of Fermi-like properties as the system enters the Tonks gas regime.