First-principles approach to spin-orbit coupling in dilute magnetic semiconductors

Abstract

We describe the implementation of a spin-polarized fully relativistic plane wave pseudopotential density functional method. Using the method, we compare the calculated electronic band structures of hypothetical ferromagnetic zinc blende structure MnAs and MnSe within the scalar-relativistic and fully relativistic pseudopotential approximations. We extract the conduction band and valence band exchange constants and extrapolate to the low concentration limit following a simple mean field approximation. Finally we investigate how strongly the exchange constants are affected by the spin-orbit term and provide a computational justification for extracting these constants from scalar-relativistic calculations.