Chiral Anomaly as the Origin of the Planar Hall Effect in Weyl Semimetals

S. Nandy, Gargee Sharma, A. Taraphder, and Sumanta Tewari

Phys. Rev. Lett. 119, 176804 – Published 24 October 2017

Abstract

In condensed matter physics, the term “chiral anomaly” implies the violation of the separate number conservation laws of Weyl fermions of different chiralities in the presence of parallel electric and magnetic fields. One effect of the chiral anomaly in the recently discovered Dirac and Weyl semimetals is a positive longitudinal magnetoconductance. Here we show that chiral anomaly and nontrivial Berry curvature effects engender another striking effect in Weyl semimetals, the planar Hall effect (PHE). Remarkably, the PHE manifests itself when the applied current, magnetic field, and the induced transverse “Hall” voltage all lie in the same plane, precisely in a configuration in which the conventional Hall effect vanishes. In this work we treat the PHE quasiclassically, and predict specific experimental signatures for type-I and type-II Weyl semimetals that can be directly checked in experiments.

Received 19 June 2017

DOI:https://doi.org/10.1103/PhysRevLett.119.176804

Physics Subject Headings (PhySH)

Topological materials Weyl semimetal

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

S. Nandy¹, Gargee Sharma², A. Taraphder^1,3, and Sumanta Tewari^1,4

¹Department of Physics, Indian Institute of Technology Kharagpur, West Bengal 721302, India
²Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
³Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, West Bengal 721302, India
⁴Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, USA