Coulomb correlation effects on the electronic structure of III-V diluted magnetic semiconductors

The effect of the Coulomb correlations in diluted magnetic III-V semiconductors has been evaluated using the LSDA+U (LSDA, local spin-density approximation) correlated band theory method. We show that Coulomb U plays an important role in determination of d-Mn states' interaction with the semiconductor host valence band. For Ga_1-xMnₓAs, we found a reasonable value of d-Mn binding energy, in agreement with the experiment. For Ga_1-xMnₓN alloy, an account of the Coulomb U turns to be even more important, removing sharp d peak from the top of the valence band, while no significant modification of Mn impurity level in the band gap is found.