Observing atom bunching by the Fourier slice theorem

TL;DR

This paper introduces a reciprocal space analysis method using the Fourier slice theorem to observe atom bunching in 3D ultracold gases, confirming fundamental quantum effects and measuring compressibility.

Contribution

It presents a novel reciprocal space technique for in situ 3D observation of atom bunching using 2D images, applicable across different dimensions.

Findings

Confirmed the role of exchange symmetry and Hanbury Brown-Twiss effect in bunching

Quantified increased isothermal compressibility through enhanced fluctuations

Demonstrated a parameter-free, calibrated measurement method

Abstract

By a novel reciprocal space analysis of the measurement, we report a calibrated in situ observation of the bunching effect in a 3D ultracold gas. The calibrated measurement with no free parameters confirms the role of the exchange symmetry and the Hanbury Brown-Twiss effect in the bunching. Also, the enhanced fluctuations of the bunching effect give a quantitative measure of the increased isothermal compressibility. We use 2D images to probe the 3D gas, using the same principle by which computerized tomography reconstructs a 3D image of a body. The powerful reciprocal space technique presented is applicable to systems with one, two, or three dimensions.