Multi-origin driven giant planar Hall effect in topological antiferromagnet EuAl2Si2 with tunable spin texture

TL;DR

This paper investigates the giant planar Hall effect in the topological antiferromagnet EuAl2Si2, revealing that classical orbital magnetoresistance and spin fluctuations dominate its behavior, with minimal influence from Berry curvature.

Contribution

It demonstrates the dominant mechanisms behind the giant PHE in EuAl2Si2 and highlights its tunable spin texture as a platform for topological and spintronic applications.

Findings

Robust PHE signal (~3.8 μΩ·cm at 2 K and 8 T) observed.

Berry curvature plays a minor role in PHE.

Classical orbital magnetoresistance and spin fluctuations are the main contributors.

Abstract

In topological materials, the planar Hall effect (PHE) is often regarded as a hallmark of profound quantum phenomena-most notably the Adler-Bell-Jackiw chiral anomaly and Berry curvature-rendering it an indispensable tool for deciphering the topological essence of emergent phases. In this study, we delve into the PHE and anisotropic magnetoresistance in the recently discovered layered topological antiferromagnet EuAl2Si2. Our analysis of the robust PHE signal (~3.8 {\mu}{\Omega} cm at 2 K and 8 T) unveils a distinct interplay of mechanisms. While Berry curvature plays a minor role, the dominant contributions stem from classical orbital MR in the field-induced ferromagnetic state and field-suppressed spin fluctuations in the paramagnetic regime. These insights not only position EuAl2Si2-with its highly tunable spin texture-as an exemplary system for probing the intricate coupling between spin configurations and band topology in magnetotransport but also pave the way for designing novel materials with tailored PHE responses, highlighting significant application prospects in quantum sensing, spintronic devices, and topologically protected electronic systems.