Spin relaxation in a two-dimensional electron gas in a perpendicular magnetic field

We consider the problem of spin relaxation in a two-dimensional electron gas (2DEG) in a perpendicular magnetic field. We assume that the spin relaxation is induced by the Rashba spin-orbit (SO) interaction, which appears due to the inversion asymmetry of the confining potential. Our solution is based on a microscopic evaluation of the spin-density response function of the 2DEG with impurities and SO interaction. We derive explicit expressions for the transverse and longitudinal spin-relaxation rates. Our analysis shows, in particular, that the spin-relaxation rates exhibit magnetoquantum oscillations, which are analogous to the Shubnikov–de Haas oscillations of the electrical resistivity. These oscillations can be observed, for example, in time-resolved optical experiments.