Mesoscopic spin transport between strongly interacting Fermi gases

We investigate mesoscopic spin transport for strongly interacting Fermi gases through a quantum point contact [1]. Under the situation in which spin polarizations in the left and right reservoirs are the same in magnitude but opposite in sign, we calculate the contribution of quasiparticles to the spin current by means of the linear response theory and many-body T-matrix approximation. For a small spin-bias regime, the current in the vicinity of the superfluid transition temperature is strongly suppressed due to the formation of pseudogaps. For a large spin-bias regime where the gases become highly polarized, on the other hand, the current is affected by the enhancement of a minority density of states due to Fermi polarons.
[1] Y. Sekino, H. Tajima, and S. Uchino, Phys. Rev. Research 2, 023152 (2020)