Ultrafast Dynamics of Intrinsic Anomalous Hall Effect in the Topological Antiferromagnet Mn3Sn

TL;DR

This study reveals the ultrafast suppression of the anomalous Hall effect in Mn3Sn driven by optical excitation, highlighting the intrinsic Berry-curvature mechanism's role and enabling new insights into nonequilibrium topological phenomena.

Contribution

It demonstrates the ultrafast dynamics of the AHE in Mn3Sn with sub-100 fs resolution, confirming the intrinsic mechanism and excluding extrinsic effects.

Findings

Ultrafast suppression of AHE observed before demagnetization.

Intrinsic Berry-curvature mechanism explains the AHE dynamics.

Extrinsic contributions are excluded in the ultrafast regime.

Abstract

We investigate ultrafast dynamics of the anomalous Hall effect (AHE) in the topological antiferromagnet Mn3Sn with sub-100 fs time resolution. Optical pulse excitations largely elevate the electron temperature up to 700 K, and terahertz probe pulses clearly resolves ultrafast suppression of the AHE before demagnetization. The result is well reproduced by microscopic calculation of the intrinsic Berry-curvature mechanism while the extrinsic contribution is clearly excluded. Our work opens a new avenue for the study of nonequilibrium AHE to identify the microscopic origin by drastic control of the electron temperature by light.