Pairing and superfluid properties of dilute fermion gases at unitarity

We study the system of a dilute gas of fermions in three dimensions, with attractive interactions tuned to the unitarity point, using the nonperturbative restricted path-integral Monte Carlo method. The pairing and superfluid properties of this system are calculated at finite temperature. The total energy at very low temperature from our results agrees closely with that of previous ground-state quantum Monte Carlo calculations. We identify the temperature T(*)approximate to 0.70 epsilon(F), below which pairing correlations develop, and estimate the critical temperature for the superfluid transition T(c)approximate to 0.245 epsilon(F) from a finite size scaling analysis of the superfluid density.