Longitudinal spin relaxation in a dilute, degenerate Fermi gas at arbitrary polarization

Abstract

We calculate the longitudinal magnetic relaxation timeT1−1 for a dilute, polarized Fermi gas with short range interactions at low temperatures. In the limit of small polarizationsT1−1 is proportional toT−2 in agreement with earlier predictions, while in the opposite caseT1−1 is strongly affected by polarization, and in the limit of large polarizations becomes proportional to the square of the energy separation between the Fermi surfaces for up and down spins. The possibility of measuringT1 in dilute solutions of3He in superfluid4He is investigated.