Terahertz Anomalous Hall Effect in Mn2-xPtSn

Abstract

Coherent-source THz spectroscopy was employed for measuring the Faraday rotation angle of Mn$_{\mathbf {2-x}}$PtSn films (x $=$ 0; 0.2). In the THz experiments, we observe clear signatures of an anomalous Hall state, while any indications of the so-called topological Hall effect recently observed in these magnetically disordered systems in dc measurements - are absent. This demonstrates that the charge scattering mechanisms, responsible for the two phenomena, possess very different time scales: the anomalous Hall state is governed by the scattering process with the rates above THz frequencies, while the electron interaction, providing the topological Hall, possesses very low characteristic time scales.