Spin-dependent phenomena in digital-magnetic heterostructures: Clustering and phase-space filling effects

Digital-magnetic heterostructures (DMH's), II-VI quantum wells with "planes " of Mn, exhibit strongly spin-dependent physics. We investigate the magnet ic-field (B) dependence of exchange-induced energy splittings and spin-flip scattering in DMH's. We find that Mn clustering is relevant to explain the magnitude and the concentration dependence of recently observed splittings . Our calculated electron spin-Rip times show "branching," i.e., tau(sf)(up -->down) decreases and tau(sf)(down-->up) increases with increasing B. This feature, consistent with recent data, is due to the B-field dependence of the available phase space. [S0163-1829(98)51848-6].