Current-induced magnetization dynamics in disordered itinerant ferromagnets
Abstract
Current-driven magnetization dynamics in ferromagnetic metals are studied in a self-consistent adiabatic local-density approximation in the presence of spin-conserving and spin-dephasing impurity scattering. Based on a quantum kinetic equation, we derive Gilbert damping and spin-transfer torques entering the Landau-Lifshitz equation to linear order in frequency and wave vector. Gilbert damping and a current-driven dissipative torque scale identically and compete, with the result that a steady current-driven domain-wall motion is insensitive to spin dephasing in the limit of weak ferromagnetism. A uniform magnetization is found to be much more stable against spin torques in the itinerant than in the \textit{s}-\textit{d} model for ferromagnetism. A dynamic spin-transfer torque reminiscent of the spin pumping in multilayers is identified and shown to govern the current-induced domain-wall distortion.
Keywords
Cite
@article{arxiv.cond-mat/0512715,
title = {Current-induced magnetization dynamics in disordered itinerant ferromagnets},
author = {Yaroslav Tserkovnyak and Hans Joakim Skadsem and Arne Brataas and Gerrit E. W. Bauer},
journal= {arXiv preprint arXiv:cond-mat/0512715},
year = {2009}
}