Beyond the Virtual Crystal Approximation in Diluted Magnetic Semiconductors

We present a new model approach which goes beyond the virtual crystal approximation and the molecular field approximation in the description of the spin splitting of band states in diluted magnetic semiconductors. The theory is formulated within a one-band effective mass approximation and explicitly takes into account a chemical and magnetic disorder caused by substitutional ions. The results confirm the apparent dependence of the p-d exchange integral on x in Cd$\text{}_{1-x}$Mn$\text{}_{x}$S for small concentrations of Mn ions and we predict the asymmetric field and temperature dependence of the spin splitting in this compound