Unveiling the interplay of magnetic order and electronic band structure on the evolution of anomalous Hall effect in MnPtGa single crystal

TL;DR

This study investigates how the complex magnetic structure and electronic band topology in MnPtGa single crystals influence the temperature-dependent sign reversal of the anomalous Hall effect, combining experimental and first-principles approaches.

Contribution

It reveals the intrinsic link between magnetic structure evolution and anomalous Hall conductivity sign reversal through combined experimental and theoretical analysis.

Findings

Sign reversal of AHE occurs around 110 K.

Magnetic structure evolution influences AHE sign change.

First-principles calculations support experimental observations.

Abstract

The recent studies on the anomalous Hall effect (AHE) have revealed an intrinsic relationship between the topological band structure and the experimentally observed transverse conductivity. Consequently, this has led to a heightened focus on examining the topological aspects of AHE. Here we have studied sign reversal of anomalous Hall conductivity with temperature in the single crystalline MnPtGa (space group: $P6_3/mmc$). From the interdependence of the linear resistance, we claim that the origin of such behavior is intrinsic. By systematically studying the electronic band structure and Berry curvature of MnPtGa using first principle calculations supported by magnetic susceptibility and isothermal magnetization measurements we demonstrate that the temperature dependent complex magnetic structure plays a significant role and leads to the sign reversal of anomalous Hall conductivity. We proposed a continuous evolution of the magnetic structure, supported by the ab initio calculations, which is consistent with the experimental data. Our studies have established that the critical temperature ($\approx$110 K), where the sign reversal appears is associated with the magnetic structure and the magnitude of Mn moments.