Spin Dynamics in Magnetic Heterostructures Driven by Current-Induced Spin-Orbit Torques

In this work it is shown that in magnetic heterostructure with the structural inversion symmetry due to the presence of the Rashba effective field responsible for the effects of spin-orbit scattering, the spin dynamics in the magnetic layer is described by a modified system of coupled equations for the exchange-coupled localized spins and spin accumulation. As a result, this system is reduced to an effective Landau-Lifshitz equation for the total magnetization with the additional torques which act similarly to the spin transfer torque in magnetic tunnel junction. Based on these equations, we calculated numerically the field dependences of the switching current density for the different magnetization geometries, in particular for that was used in work of Miron et al., which are in a good agreement with the experimental results for the reasonable fitting parameters.