Planar Hall effect with sixfold oscillations in a Dirac antiperovskite
D. Huang, H. Nakamura, H. Takagi
Abstract
The planar Hall effect (PHE), wherein a rotating magnetic field in the plane of a sample induces oscillating transverse voltage, has recently garnered attention in a wide range of topological metals and insulators. The observed twofold oscillations in yx as the magnetic field completes one rotation are the result of chiral, orbital, and/or spin effects. The antiperovskites A 3 BO (A = Ca, Sr, Ba; B = Sn, Pb) are topological crystalline insulators whose low-energy excitations are described by a generalized Dirac equation for fermions with total angular momentum J = 3 2 . We report unusual sixfold oscillations in the PHE of Sr 3 SnO, which persisted nearly up to room temperature. Multiple harmonics (twofold, fourfold, and sixfold), which exhibited distinct field and temperature dependencies, were detected in xx and yx . These observations are more diverse than those in other Dirac and Weyl semimetals and point to a richer interplay of microscopic processes underlying the PHE in the antiperovskites.