NONEQUILIBRIUM SPIN AND SPIN FLUX IN QUANTUM FILMS OF GAAS-TYPE SEMICONDUCTORS

Theoretical analysis has been performed on the relationship between th e nonequilibrium spin and the spin flux, which arises for carriers in an asymmetrical quantum well or in a quantum well (QW) in semiconducto rs without an inversion center. It has been shown that in the presence of a nonequilibrium spin with density S, the correlation between the spin and the momentum of carriers leads to a spin flux J in the QW pla ne. In its turn, this spin flux produces the nonequilibrium spin polar ization. The most typical manifestations of the relationship between S and J have been considered, in particular, spin relaxation by Dyakono v-Perel mechanism and the appearance of an effective magnetic field in the case of the directional motion of the carriers.