Detection of spatial correlations in an ultracold gas of fermions

Spatial correlations in a ultracold gas of fermions atoms close to Feshbach resonance were detected. By inducing spin-changing radiofrequency transitions between pairs of atoms the correlation were detected. The process was observed in the strongly interaction regime for attractive as well as for repulsive atom-atom interactions and both in the regime of high and low quantum degeneracy. The results shows that a Feshbach resonance increases the strength of atom-atom interactions and introduces strong pair correlations between atoms for both positive and negative magnetic-fields from the resonance.