Density correlations in ultracold atomic Fermi gases

We investigate density fluctuations in a coherent ensemble of interacting fermionic atoms around the BEC-BCS crossover. Adapting the concept of full counting statistics, well-known from quantum optics and mesoscopic electron transport, we study second-order as well as higher-order correlators of density fluctuations. This method is applied to the crossover from a molecular BEC state to a fermionic BCS state and yields a transition from Poissonian statistics to binomial statistics. The statistics can thus be used as an experimental tool to gain information on the many-body ground state in the crossover regime.