Unidirectional magnetoresistance in a nonmagnetic topological insulator with hexagonal warping in the surface states.

ORAL

Abstract

Unidirectional magnetoresistance (UMR) was recently observed in various bilayers consisting of a paramagnetic and a ferromagnetic material, arising from the interplay of spin accumulation and spin dependent scattering. In this work [1], we report the emergence of a novel UMR effect in a non-magnetic topological insulator (TI) layer, which scales linearly with the applied electric and magnetic fields. We show theoretically that this UMR originates from the conversion of a nonlinear spin current in the hexagonally warped surface states to a nonlinear charge current. Remarkably, with an out-of-plane magnetic field, the UMR also depends on the orientation of the current with respect to the crystallographic axes, exhibiting a three-fold rotational symmetry around the axis perpendicular to the [111] surface of the TI layer. This unique feature can be used to map the spin texture of the TI surface states based on the angular dependence of the UMR, alternative to ARPES.
[1] P. He, S. S.-L. Zhang, D. Zhu, Y. Liu, Y. Wang, J. Yu, G. Vignale & H. Yang, arXiv:1706.09589.

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Presenters

  • Pan He

    Dept. of Electrical and Computer Engineering, National Univ. of Singapore

Authors

  • Pan He

    Dept. of Electrical and Computer Engineering, National Univ. of Singapore

  • Shulei Zhang

    Materials Science, Argonne National Laboratory, Argonne Natl Lab, Materials Science Division, Argonne Nat'l Lab; Dept. of Physics and Astronomy, Univ. of Missouri, Material Science Division, Argonne Nat'l Lab; Dept. of Physics and Astronomy, Univ. of Missouri

  • Dapeng Zhu

    Department of Electrical and Computer Engineering, National University of Singapore, Dept. of Electrical and Computer Engineering, National Univ. of Singapore

  • Yang Liu

    Dept. of Electrical and Computer Engineering, National Univ. of Singapore

  • YI Wang

    Dept. of Electrical and Computer Engineering, National Univ. of Singapore, Electrical and Computer Engineering, National University of Singapore

  • JIAWEI YU

    Dept. of Electrical and Computer Engineering, National Univ. of Singapore

  • Giovanni Vignale

    Physics, University of Missouri, Physics and Astronomy, University of Missouri - Columbia, Univ of Missouri - Columbia, Physics and Astronomy, University of Missouri, Dept. of Physics and Astronomy, Univ. of Missouri

  • Hyunsoo Yang

    National University of Singapore, Department of Electrical and Computer Engineering, National University of Singapore, Dept. of Electrical and Computer Engineering, National Univ. of Singapore, Electrical and Computer Engineering, National University of Singapore