Signatures of resonance superfluidity in a quantum Fermi gas

We will consider the superfluid phase transition that arises when a Feshbach resonance pairing occurs in a dilute Fermi gas. Observation of superfluidity in such systems may provide the opportunity to experimentally study the crossover from the momentum correlated superfluidity of weakly-coupled fermions to the Bose-Einstein condensation of strongly-bound composite bosons. We will discuss a direct and observable signature of the superfluid transition by applying the theory to a gas confined in a harmonic potential(M.L. Chiofalo, S.J.J.M.F. Kokkelmans, J.N. Milstein, M.J. Holland, to be published in PRL, also available as e-print cond-mat/0110119.). The signature of the phase transition is given by a significant increase in density observed in the vicinity of the trap center. This increase in density is due to the difference in compressibility of the superfluid and normal phases.