Scattering theory of charge-current-induced magnetization dynamics

In ferromagnets, charge currents can excite magnons via the spin-orbit coupling. We develop a novel and general scattering theory of charge-current-induced macrospin magnetization torques in normal metal vertical bar ferromagnet vertical bar normal metal layers. We apply the formalism to a dirty GaAs vertical bar(Ga, Mn)As vertical bar GaAs system. By computing the charge-current-induced magnetization torques and solving the Landau-Lifshitz-Gilbert equation, we find magnetization switching for current densities as low as 5 x 10(6) A/cm(2). Our results are in agreement with a recent experimental observation of charge-current-induced magnetization switching in (Ga, Mn)As. Copyright (C) EPLA, 2010