Efficient spin transfer torque in pseudo-spin-valve structure

Abstract

A generalized spin transport model is applied to a typical pseudo-spin-valve (PSV) structure, consisting of a Co1 (10 nm) -Cu (6 nm) -Co2 (3 nm) trilayer with noncollinear magnetization. The model is based on the spin-drift-diffusion model, which considers both longitudinal and transverse components of spin accumulation and spin current across the PSV. The influence of a spin-selective interfacial resistance is incorporated by modifying the boundary conditions. The strength of the spin transfer torque is obtained by considering the transverse spin accumulation in the free layer. Our calculations predict a significant enhancement of spin torque and consequent reduction in the critical current density for current-induced magnetization switching by engineering the spin-dependent interfacial effects and optimizing the relative orientations of the anisotropy axes of the two ferromagnetic layers. © 2008 American Institute of Physics.