Noncollinear spin transfer in Co/Cu/Co multilayers (invited)

This article has two parts. The first part uses a single point of view to discuss the reflection and averaging mechanisms of spin transfer between current-carrying electrons and the ferromagnetic layers of magnetic/nonmagnetic heterostructures. The second part incorporates both effects into a matrix Boltzmann equation and reports numerical results for current polarization, spin accumulation, magnetoresistance, and spin-transfer torques for Co/Cu/Co multilayers. When possible, the results are compared quantitatively with relevant experiments.