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arXiv · 1810.05828

Spin-torque resonance due to diffusive dynamics at a surface of topological insulator

R. J. Sokolewicz·I. A. Ado·M. I. Katsnelson·P. M. Ostrovsky·M. Titov
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Abstract

We investigate spin-orbit torques on magnetization in an insulating ferromagnetic (FM) layer that is brought into a close proximity to a topological insulator (TI). In addition to the well-known field-like spin-orbit torque, we identify an anisotropic anti-damping-like spin-orbit torque that originates in a diffusive motion of conduction electrons. This diffusive torque is vanishing in the limit of zero momentum (i. e. for spatially homogeneous electric field or current), but may, nevertheless, have a strong effect on spin-torque resonance at finite frequency provided external field is neither parallel nor perpendicular to the TI surface. The required electric field configuration can be created by a grated top gate.

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R. J. Sokolewicz, I. A. Ado, M. I. Katsnelson, P. M. Ostrovsky, M. Titov. 2019-05-23. Spin-torque resonance due to diffusive dynamics at a surface of topological insulator. https://doi.org/10.1103/physrevb.99.214444

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