Electronic structure of diluted magnetic semiconductors and their superlattices

We report the KKR-CPA-LDA (Korringa-Kohn-Rostoker, coherent-potential appro ximation and the local density approximation) electronic structure calculat ions of the diluted magnetic semiconductor (DMS) (In, Mn)hs and superlattic es of DMSs, (In, Mn)As/(Al, Be)Sb and (Cd, Mn)Te/Ga(As, Ca). The magnetic p roperties of DMSs are strongly affected by the existence of d holes through Zener's double exchange. Since the hole density at the (In, Mn)As layer de pends on that at (Al, Be)Sb, the magnetic properties of (In, Mn)As/(Al, Be) Sb are also controllable by adjusting the Be concentration. The calculation s confirm that this indeed is the case and that the mechanism may be used t o control the magnetism of DMSs. It is also pointed out that the superlatti ces open up the possibility of the ferromagnetism in the II-VI based DMSs.