Anomalous fermion bunching in density-density correlation

Abstract

We consider theoretically density-density correlation of identical Fermi system by including the finite resolution of a detector and delta-function term omitted in the ordinary method. We find an anomalous fermion bunching effect, which is a quantum effect having no classical analogue. This anomalous fermion bunching is studied for ultracold Fermi gases released from a three-dimensional optical lattices. It is found that this anomalous fermion bunching is supported by a recent experiment (T. Rom et al Nature 444, 733 (2006)).