We study the magnetic damping in the simplest of synthetic antiferromagnets, i.e. antiferromagnetically exchange-coupled spin valves in which applied magnetic fields tune the magnetic configuration to become noncollinear. We formulate the dynamic exchange of spin currents in a noncollinear texture based on the spindiffusion theory with quantum mechanical boundary conditions at the ferrromagnet|normal-metal interfaces and derive the Landau-Lifshitz-Gilbert equations coupled by the static interlayer non-local and the dynamic exchange interactions. We predict non-collinearity-induced additional damping that can be sensitively modulated by an applied magnetic field. The theoretical results compare favorably with published experiments.
@article{arxiv.1504.06042,
title = {Magnetization damping in noncollinear spin valves with antiferromagnetic interlayer couplings},
author = {Takahiro Chiba and Gerrit E. W. Bauer and Saburo Takahashi},
journal= {arXiv preprint arXiv:1504.06042},
year = {2015}
}