Spin polarization and band alignments at NiMnSb/GaAs interface

We focus here on the NiMnSb/GaAs(0 0 1) heterojunction that we investigate by accurate pseudopotential density functional-local spin density calculations. We find in general that the half-metallicity is lost when NiMnSb is joined with the semiconductor, even at the interface with a mixed (Mn,As) plane which is one of the most promising for maintaining the desired half-metallicity. In this case, however, the effect is localized just on the interfacial atoms. Electronic and magnetic bulk properties are recovered within a couple of atomic planes far from the interface, so that the band alignments are well defined.