Nonlinear Hall effect induced by anomalous skew scattering in PT-symmetric systems

We uncover a new mechanism of the nonlinear Hall effect in PT-symmetric systems. Although skew scattering and Berry curvature are both PT-odd, the combination of the two is PT-even, giving rise to the anomalous skew scattering nonlinear Hall effect (ASN). ASN grows with increasing relaxation time, and it diverges in the clean limit. Strikingly, we find that ASN supports a helicity dependent photocurrent even in a PT symmetric metal in contrast to all other metallic second order nonlinear photocurrents that are insensitive to helicity: this enables means to directly isolate ASN. We anticipate that accounting for ASN will provide additional tools in diagnosing the antiferromagnetic order of PT-symmetric metals.

This work is funded by Singapore MOE Academic Research Fund Tier 3 Grant MOE2018-T3-1-002 and a Nanyang Technological University start-up grant (NTU-SUG).