Description of the exchange effects in dilute magnetic semiconductor quantum structures

Based on our extended generalized pair approximation, a theoretical method is presented which realistically describes the exchange-interaction effects in dilute magnetic semiconducting quantum structures with moderate magnetic ion concentrations (x less than or equal to 10%). As an illustration of our approach, we have calculated the Zeeman splittings in Cd1-xMnxTe showing clearly the correlation between the mean spin projection of magnetic ions and the related p-d and d-d exchange integrals. On the other hand, our analysis of the Zeeman splittings in Cd1-xMnxTe/Cd1-x-yMnxMgyTe quantum structures with different well widths demonstrates that the data are well described, within the experimental error, with the bulk values of the sp-d and d-d exchange-interaction constants. (C) 1998 Elsevier Science B.V. All rights reserved.