Role of external electric field and spin-orbit coupling in magneto-transport properties at ferromagnetic metal/MgO interfaces*

Electric-field (E-field) induced modification of magnetism in transition-metal thin-films has been shown as a potential approach offering the promising pathway to control magnetism. Previously, we have investigated the E-field induced modification of the magnetocrystalline anisotropy (MCA) at an Fe/MgO interface and at that with an insertion of heavy-metals from first-principles.[1] We here extend the investigation to magneto-transport properties in an E-field. Calculations were carried out using the FLAPW method in which the conductivity tensor was obtained by applying the linear response theory. By insertion of heavy metals of 5d (Os, Ir, Pt) at the Fe/MgO interface, we find that the E-field induced MCA modification is dramatically improved. On the other hands, the tunneling magnetoresistance ratio decreases upon the insertion, where the reduction may be explained by the exchange splitting and SOC strength of the insertion elements. The anomalous/spin Hall conductivities are furthermore found to modified by an application of E-field. [1] K. Nakamura, et.al., PRB 81, 220409R (2010); JMMM 429, 214 (2017).