APS Logo

Nonlinear Hall effect in the spin-valley locked Dirac semimetal BaMnSb<sub>2</sub>

ORAL

Abstract

In time-reversal invariant materials, Berry curvature dipole (BCD) gives rise to an anomalous nonlinear Hall effect (NLHE) when the inversion symmetry is broken. Although NLHE is observed in bilayer[1] and few-layer[2] WTe2, BCD-induced NLHE in bulk single-crystals remains elusive. In this talk, we will report a bulk NLHE in a spin-valley locked Dirac semimetal BaMnSb2[3]. In this material, the distorted Sb zig-zag chains generate two gapped Dirac cones with spin-valley locking near the X point in the Brillouin zone, which creates a BCD. Our experiments show when an alternating current flows along the zig-zag chain direction across the crystal, a second-order Hall signal is present and exhibits the quadratic dependence on current. Through structure and domain tuning, we further demonstrate the observed NLHE is intrinsic. This finding shows NLHE measurements can serve as a probe for Berry curvature for non-centrosymmetric bulk crystals.

[1] Q. Ma, et al., Nature 565, 337 (2019).
[2] K. Kang, et al., Nat. Mater. 18, 324 (2019).
[3] J. Y. Liu, et al., ArXiv:1907.06318.

–

Presenters

  • Lujin Min

    Department of Material Science and Engineering, Penn State University, Department of Physics, Pennsylvania State University, Physics, Pennsylvania State University, Pennsylvania State University, Department of Materials Science and Engineering, Pennsylvania State University

Authors

  • Lujin Min

    Department of Material Science and Engineering, Penn State University, Department of Physics, Pennsylvania State University, Physics, Pennsylvania State University, Pennsylvania State University, Department of Materials Science and Engineering, Pennsylvania State University

  • Venkatraman Gopalan

    Pennsylvania State University, Material Science and Engineering, Pennsylvania State University, Department of Material Science and Engineering, Penn State University, Department of Materials Science and Engineering, Pennsylvania State University, Materials Science and Engineering, Pennsylvania State University

  • Zhiqiang Mao

    Pennsylvania State University, Department of Physics, Penn State University, The Pennsylvania State University, Penn State University, Physics, Penn State University, Department of Physics, Pennsylvania State University, Department of Physics, The Pennsylvania State University, Physics, The Pennsylvania State University, Physics, Pennsylvania State University, Department of Materials Science and Engineering, Pennsylvania State University