First-principles Study on the Magnetic Interaction in ZnO-based Dilute Magnetic Semiconductors

Using first-principles calculations, we investigate the electronic structures and magnetic properties of dilute magnetic semiconductors (DMS). The electronic structures are calculated by using Korringa-Kohn-Rostoker method combined with the coherent potential approximation. Since the d electrons of the magnetic impurity in DMS are strongly localized, we apply self-interaction correction to the local density approximation for the exchange-correlation energy. From the first-principles results, we evaluate the magnetic exchange interaction $J_{ij}$ between the pairs of magnetic impurities by using the Lichtenstein's formula. We found that the magnetic interaction in ZnO-based DMS is basically antiferromagnetic without any additional carrier because of large energy gaps between the occupied and unoccupied d states. We will also discuss about the carrier dependence of the magnetic interaction in ZnO-based DMS.