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arXiv · 2111.03397

Non-linear antidamping spin-orbit torque originating from intra-band transport on the warped surface of a topological insulator

Yong-Long Zhou·Hou-Jian Duan·Yong-jia Wu·Ming-Xun Deng·Lan Wang·Dimitrie Culcer·Rui-Qiang Wang
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Abstract

Motivated by recent experiments observing a large antidamping spin-orbit torque (SOT) on the surface of a three-dimensional topological insulator, we investigate the origin of the current-induced SOT beyond linear-response theory. We find that a strong antidamping SOT arises from intraband transitions in non-linear response, and does not require interband transitions as is the case in linear transport mechanisms. The joint effect of warping and an in-plane magnetization generates a non-linear antidamping SOT which can exceed the intrinsic one by several orders of magnitude, depending on warping parameter and the position of Fermi energy, and exhibits a complex dependence on the azimuthal angle of the magnetization. This nonlinear SOT provides an alternative explanation of the observed giant SOT in recent experiments.

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Yong-Long Zhou, Hou-Jian Duan, Yong-jia Wu, Ming-Xun Deng, Lan Wang, Dimitrie Culcer, Rui-Qiang Wang. 2021-11-05. Non-linear antidamping spin-orbit torque originating from intra-band transport on the warped surface of a topological insulator. https://doi.org/10.1103/physrevb.105.075415

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