Spin-Polarized Current and Spin-Transfer Torque in Magnetic Multilayers

Abstract

We expose the theory of quantized spin-polarized electron transport perpendicular to the plane of a magnetic multilayer with non-collinear magnetization vectors. The dependence of resistance and current-driven torque on relative angle between 2 magnetic moments of a multilayer pillar are derived. Spacers of both metallic and insulating tunnel-barrier types are considered. The classical Landau-Lifshitz equation describes the dynamics of the magnetization created by spintransfer torque.