From low-density neutron matter to the unitary limit

Abstract

Various quantities of an attractively interacting fermion system at the unitary limit are determined by extrapolating Monte Carlo results of low-density neutron matter. Smooth extrapolation in terms of $1/({k}_{F}{a}_{0})$ (${k}_{F}$ is the Fermi momentum, and ${a}_{0}$ is the ${}^{1}{S}_{0}$ scattering length) is found with the quantities examined: the ground-state energy, the pairing gap at $T\ensuremath{\approx}0$, and the critical temperature of the normal-to-superfluid phase transition. We emphasize proximity of the physics of low-density neutron matter to that at the unitary limit. The extrapolated quantities are in a reasonable agreement with those in the literature.