Detection of spatial correlations in an ultracold gas of fermions

TL;DR

This paper reports the observation of spatial correlations in an ultracold fermionic gas near a Feshbach resonance, using spin-changing rf transitions to detect correlations across various interaction regimes and degeneracy levels.

Contribution

It introduces a method to detect spatial correlations in ultracold fermions via rf transitions and compares experimental results with a two-particle theoretical model.

Findings

Correlations observed in both attractive and repulsive regimes.

Detection method effective across different quantum degeneracy levels.

Experimental results agree with theoretical predictions.

Abstract

Spatial correlations are observed in an ultracold gas of fermionic atoms close to a Feshbach resonance. The correlations are detected by inducing spin-changing rf transitions between pairs of atoms. We observe the process in the strongly interacting regime for attractive as well as for repulsive atom-atom interactions and both in the regime of high and low quantum degeneracy. The observations are compared with a two-particle model that provides theoretical predictions for the measured rf transition rates.