Planar Hall effect with sixfold oscillations in a Dirac antiperovskite

TL;DR

This study reports the observation of sixfold oscillations in the planar Hall effect of Sr₃SnO, a Dirac antiperovskite, revealing complex underlying microscopic processes and extending understanding of topological crystalline insulators.

Contribution

It uncovers sixfold oscillations in the PHE of Sr₃SnO, demonstrating more diverse harmonic behavior than in other Dirac and Weyl semimetals, indicating richer microscopic interactions.

Findings

Sixfold oscillations in PHE observed in Sr₃SnO

Multiple harmonics with distinct field and temperature dependencies

Persistence of effects nearly up to room temperature

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 $\rho_{yx}$ as the magnetic field completes one rotation are the result of chiral, orbital and/or spin effects. The antiperovskites $A_3B$O ($A$ = 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 $\rho_{xx}$ and $\rho_{yx}$. 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.