Extracting density-density correlations from in situ images of atomic quantum gases

TL;DR

This paper provides a comprehensive method to extract and analyze density-density correlations and the static structure factor from in situ images of 2D atomic quantum gases, accounting for imaging aberrations and exploring different interaction regimes.

Contribution

It introduces a complete recipe for extracting correlations from in situ images, including correction for imaging aberrations, and applies it to both weakly and strongly interacting 2D gases.

Findings

Successful removal of imaging aberration effects.

Measurement of static structure factor in various interaction regimes.

Observation of suppression of structure factor at long wavelengths in strongly interacting gases.

Abstract

We present a complete recipe to extract the density-density correlations and the static structure factor of a two-dimensional (2D) atomic quantum gas from in situ imaging. Using images of non-interacting thermal gases, we characterize and remove the systematic contributions of imaging aberrations to the measured density-density correlations of atomic samples. We determine the static structure factor and report results on weakly interacting 2D Bose gases, as well as strongly interacting gases in a 2D optical lattice. In the strongly interacting regime, we observe a strong suppression of the static structure factor at long wavelengths.