Anomalous Skew-Scattering Nonlinear Hall Effect and Chiral Photocurrents in PT-Symmetric Antiferromagnets

Berry curvature and skew scattering play central roles in determining both the linear and nonlinear anomalous Hall effects. Yet in PT-symmetric antiferromagnetic metals, Hall effects from either intrinsic Berry curvature mediated anomalous velocity or the conventional skew-scattering process individually vanish. Here we reveal an unexpected nonlinear Hall effect that relies on both Berry curvature and skewscattering working in cooperation. This anomalous skew-scattering nonlinear Hall effect (ASN) is PT even and dominates the low-frequency nonlinear Hall effect for PT-symmetric antiferromagnetic metals. Surprisingly, we find that in addition to its Hall response, ASN produces helicity dependent photocurrents, in contrast to other known PT-even nonlinearities in metals that are helicity blind. This characteristic enables us to isolate ASN and establishes new photocurrent tools to interrogate the antiferromagnetic order of PT-symmetric metals.

Automated summary

Berry curvature and skew scattering are important for the anomalous Hall effect in antiferromagnetic metals. In PT-symmetric antiferromagnetic metals, the Hall effects individually vanish. However, we reveal a new nonlinear Hall effect (ASN) that relies on both Berry curvature and skew scattering working together. This ASN produces helicity dependent photocurrents, which can be used to investigate the antiferromagnetic order in PT-symmetric metals.