Sign-reversal Anomalous Hall effect driven by a magnetic transition in Cr$_{7-\delta}$Te$_8$

TL;DR

This study reveals a magnetic transition in Cr$_{7-eta}$Te$_8$ that causes a sign reversal in the anomalous Hall effect and exhibits a significant topological Hall effect at room temperature, linked to complex magnetic interactions.

Contribution

It reports the discovery of a magnetic transition and associated sign change in the anomalous Hall effect, along with a large topological Hall effect in Cr$_{7-eta}$Te$_8$, a novel observation in this material.

Findings

Magnetic transition causes sign reversal in anomalous Hall effect.

Large topological Hall effect observed without breaking inversion symmetry.

The effects persist up to room temperature due to spin chirality.

Abstract

The search for exotic spin configurations and related novel transport properties continues to be fueled by the promise of new electronic states and outstanding candidate components for spintronic applications. In layered Cr$_{7-\delta}$Te$_8$, the applied field drives a before unreported magnetic transition revealed by the alternating current magnetic susceptibility measurements around room temperature. This observed magnetic transition results in a sign change for the anomalous Hall effect which exhibits non-monotonous temperature dependence. The prominent topological Hall effect (THE) with a large value of 1$\mu \Omega \cdot cm$ has been observed without breaking the inversion symmetry for Cr$_{7-\delta}$Te$_8$. This robust THE can persist up to room temperature attributed to the nonzero fluctuation-driven scalar spin chirality. The complicated interactions of long-range and short-range magnetic orders lead to rich exotic magnetic states with related novel transport properties in Cr$_{7-\delta}$Te$_8$.