Pairing and Superfluid Properties of Dilute Fermion Gases at Unitarity

We study the pairing and superfluid properties of a dilute gas of fermions in 3-dimensions with attractive interactions tuned to the unitarity point [1]. The finite temperature, non- perturbative, Restricted Path Integral Monte Carlo (R-PIMC) method is used for our simulations and tested against previous ground-state Quantum Monte Carlo calculations. From the growth of the density correlations for unequal spins, we identify the pseudogap crossover temperature scale T*~0.70 Ef below which pairing correlations develop. We estimate the critical temperature for condensation Tc~0.24 Ef from a finite size scaling analysis of the superfluid density. The pseudogap phase is characterised by the spin susceptibility and compressibility. We will also present results for unequal populations of fermions. \newline \newline [1] V. Akkineni, N. Trivedi, D.M. Ceperley, cond-mat/0608154