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arXiv · 1705.07947

Semiclassical theory of spin-orbit torques in disordered multiband electron systems

Cong Xiao·Qian Niu
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Abstract

We study spin-orbit torques (SOT) in non-degenerate multiband electron systems in the weak disorder limit. In order to have better physical transparency a semiclassical Boltzmann approach equivalent to the Kubo diagrammatic approach in the non-crossing approximation is formulated. This semiclassical framework accounts for the interband- coherence effects induced by both the electric field and static impurity scattering. Using the two-dimensional Rashba ferromagnet as a model system, we show that the antidamping-like SOT arising from disorder-induced interband-coherence effects is very sensitive to the spin structure of disorder and may have the same sign as the intrinsic SOT in the presence of spin-dependent disorder. While the cancellation of this SOT and the intrinsic one occurs only in the case of spin-independent short-range disorder.

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Cong Xiao, Qian Niu. 2017-05-22. Semiclassical theory of spin-orbit torques in disordered multiband electron systems. https://doi.org/10.1103/physrevb.96.045428

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