Significant electron-magnon scattering in layered ferromagnet Cr$_2$Te$_3$

TL;DR

This paper demonstrates that electron-magnon scattering significantly influences the anomalous Hall effect in layered ferromagnet Cr$_2$Te$_3$, explaining the temperature-dependent sign change through magnon-induced skew scattering.

Contribution

It reveals that electron-magnon skew scattering plays a dominant role in the AHE of Cr$_2$Te$_3$, a novel insight into the interplay of magnons and electronic transport in layered ferromagnets.

Findings

Electron-magnon skew scattering contributes significantly to AHE.

The sign change in AHE is due to competition between different scattering mechanisms.

Magnon-induced skew scattering can dominate AHE in layered ferromagnets with heavy elements.

Abstract

A layered ferromagnet Cr$_2$Te$_3$ is attracting growing interest because of its unique electronic and magnetic properties. Studies have shown that it exhibits sizable anomalous Hall effect (AHE) that changes sign with temperature. The origin of the AHE and the sign change, however, remains elusive. Here we show experimentally that electron-magnon scattering significantly contributes to the AHE in Cr$_2$Te$_3$ through magnon induced skew scattering, and that the sign change is caused by the competition with the Berry-curvature or impurity-induced side-jump contribution. The electron-magnon skew scattering is expected to arise from the exchange interaction between the itinerant Te $p$-electrons and the localized Cr $d$-electrons modified by the strong spin-orbit coupling on Te. These results suggest that the magnon-induced skew scattering can dominate the AHE in layered ferromagnets with heavy elements.