Electronic structure and magnetism of diluted magnetic semiconductors-a first principles study

We present first-principles electronic structure calculations within density functional theory using a plane-wave pseudopotential method for Mn-doped diluted magnetic semiconductors. In particular, we show here a comparative study of Mn-doped GaAs and GaN systems and conclude that the origin of ferromagnetic long-range order is different for the two cases. Finally, we show theoretical simulations of scanning tunelling microscope (STM) images in Mn-doped GaAs. The simulated images with Mn in second Ga layer from a GaAs(1 1 0) surface are in excellent agreement with the experimental images