Transport of spin and mass at normal-superfluid interfaces in the unitary Fermi gas

Transport in strongly interacting Fermi gases provides a window into the nonequilibrium behavior of correlated fermions. In particular, interface between polarized normal gas and weakly superfluid at finite temperature presents model for understanding transport normal-superfluid normal-superconductor interfaces. An excess polarization phase or deficit brings system out equilibrium, leading to currents across interface. We implement phenomenological mean-field unitary gas, investigate spin mass under conditions. consider independently prepared regions brought contact, calculate instantaneous (NS) For an unpolarized superfluid, we find that current is suppressed below threshold value driving chemical potential differences, while nearly vanishes critically superfluid. The can exhibit cases where Andreev reflection vanishes, general prevents occurrence current. Our results provide guidance future experiments aiming characterize NS