Normal state of a polarized Fermi gas at unitarity
Abstract
We study the Fermi gas at unitarity and at T=0 by assuming that, at high polarizations, it is a normal Fermi liquid composed of weakly interacting quasiparticles associated with the minority spin atoms. With a quantum Monte Carlo approach we calculate their effective mass and binding energy, as well as the full equation of state of the normal phase as a function of the concentration x=n_\down/n_\up of minority atoms. We predict a first order phase transition from normal to superfluid at x_c=0.44 corresponding, in the presence of harmonic trapping, to a critical polarization P_c=(N_\up-N_\down)/ (N_\up+N_\down)=77%. We calculate the radii and the density profiles in the trap and predict that the frequency of the spin dipole mode will be increased by a factor of 1.23 due to interactions.
Keywords
Cite
@article{arxiv.cond-mat/0607730,
title = {Normal state of a polarized Fermi gas at unitarity},
author = {C. Lobo and A. Recati and S. Giorgini and S. Stringari},
journal= {arXiv preprint arXiv:cond-mat/0607730},
year = {2009}
}