Electronic structure and exchange interaction in Ga sub(1-x)

We have calculated the electronic structure of Ga sub(1-x )Mn sub( x )As and In sub(1-x )Mn sub( x )Sb diluted magnetic semiconductors and shown that, in agreement with recent photoelectron spectroscopy data, the Mn 4s and Mn 3d orbitals are hybridized with the valence band of the host semiconductor. A new approach has been developed for calculating exchange interaction in diluted magnetic semiconductors, which is based on the spin polarization of s-electrons at a magnetic center due to single-center exchange s-d matrix elements. The magnitude of exchange interaction calculated using Hartree-Fock atomic wave functions and the electrondensity-functional approach agrees well with previous data.