Critical correlations in an ultracold Bose gas revealed by means of a temporal Talbot-Lau interferometer

TL;DR

This paper experimentally investigates critical correlations in an ultracold Bose gas using a temporal Talbot-Lau interferometer, revealing a peak in the density distribution near the critical temperature that aligns with theoretical predictions.

Contribution

It introduces an experimental method employing a temporal Talbot-Lau interferometer to probe critical correlations in ultracold Bose gases, providing direct measurement of critical exponents.

Findings

Observation of a bi-modal density distribution near the critical temperature.

Identification of a peak in the narrow component fraction within the critical regime.

Critical exponents extracted match theoretical predictions for correlation length.

Abstract

We study experimentally the critical correlation in an ultra-cold Bose gas with a temporal Talbot-Lau (TL) interferometer. Near the critical temperature, we observe a bi-modal density distribution in an ultra-cold Bose gas after the application of the TL interferometer. The measured fraction of the narrower peak in the density distribution displays a clear peak within the critical regime. The peak position agrees with the critical temperature calculated with the finite-size and interaction corrections. The critical exponents are extracted from the peak and they agree with the critical exponents for the correlation length.