Low-temperature spin diffusion in a spin-polarized fermi gas

We present a finite temperature calculation of the transverse spin-diffusion coefficient D in a dilute degenerate Fermi gas, in the presence of a small external magnetic field H. While the longitudinal diffusion coefficient displays the conventional Fermi-liquid dependence, DT-2, the behavior of D shows three separate regimes: (a) D∼H-2 for TH, (b) D∼T-2, DD1 for TH and large spin-rotation parameter ξ1, and (c) D=DT-2 for TH and ξ1. Our results are qualitatively consistent with the experimental data in weakly spin-polarized He3 and He3- He4 mixtures.