Landau-Lifshitz equations and spin dynamics in a heterostructure with a broken inversion symmetry, under spin-orbit torque transfer of the spin moment

Abstract

The Landau-Lifshitz equations are generalized to the case of spin accumulation and dynamics of localized spins in the conductive magnet, in terms of the Rashba spin-orbit scattering mechanism. The effects of the spin-orbit transfer torque caused by longitudinal current flowing through the conducting heterostructure with a thin magnetic layer, on the spin state of the structure, are analyzed in the macrospin approximation on the basis of modified Landau-Lifshitz equations. It is found that the possibility of realizing the spin switch modes in the magnetic layer of the heterostructure with an easy-plane magnetic layer exists, and depends on the geometry of the magnetization, which is also the case for transverse spin-transfer torque in spin-valve structures. We built examples of diagrams of spin states on the current-field plane, that show a satisfactory agreement between the results of the experimental measurements of the critical fields and spin switching currents in the magnetic layers of asymmetric hete...