Ab initio calculations of transport properties of epitaxial (Ga,Mn)As systems

Abstract

We calculate transport properties of thin ( Ga , Mn ) As layers sandwiched between two Cr ( 0 0 1 ) leads as a function of Mn concentration and layer thickness, special attention is paid to the spin polarization of the current-perpendicular-to-plane (CPP) conductance. We compare our results to bulk properties. Doping GaAs with Mn increases occurrence of As antisites on the Ga sublattice. Our method allows us to take into account even very small defect concentration changes, and we show that it may have a dramatic impact on the CPP spin polarization, apart from its already known influence on Curie temperatures.