IMSc Webinar

Chiral planar Hall effect in Weyl semimetals

Debabrata Sinha

Indian Institute of Technology, Kharagpur

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The planar Hall effect (PHE), the appearance of an in-plane transverse voltage in the presence of co-planar electric (E) and magnetic (B) fields, occurs in Weyl semimetals (WSMs) as one of the fundamental manifestations of chiral anomaly represented by a E.B term. We demonstrate here that PHE can survive in an inhomogeneous Weyl semimetal (IWSM) even in the absence of the aforesaid anomaly. Using a semiclassical Boltzmann transport theory, we show that PHE could also appear in an IWSM due to the strain-induced chiral gauge potential, which couples to the Weyl fermions of opposite chirality with opposite sign. Our study shows a resultant phase shift in the current associated with opposite chirality Weyl nodes, which, remarkably, leads to a finite chirality-dependent planar Hall effect (CPHE) in the IWSMs. Interestingly, we show that a small tilt in the Weyl node can generate a pure CPHE even in the absence of an applied magnetic field. The CPHE finds an important implication in `chiralitytronics'. We also discuss the experimental feasibility of these novel effects of strain in type-I IWSMs.

Ref: Phys. Rev. B 102, 121105 (R) 2020