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 magnetic-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-flip times show ‘‘branching,’’ i.e., ts f up→down decreases and ts f 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#