Chiral-anomaly-driven magnetotransport in the correlated Weyl magnet Mn$_3$Sn

TL;DR

This study investigates how electronic correlations affect the chiral anomaly in the magnetic Weyl semimetal Mn$_3$Sn by examining magnetotransport properties across different doping levels, revealing the persistence of the anomaly despite strong correlations.

Contribution

It provides the first systematic analysis of the interplay between electronic correlations and the chiral anomaly in Mn$_3$Sn, demonstrating the anomaly's robustness in a strongly correlated system.

Findings

Negative longitudinal magnetoresistance observed

Planar Hall effect linked to the chiral anomaly detected

Chiral anomaly persists despite strong electronic correlations

Abstract

The quest for topological states in strongly correlated materials is challenging but essential from fundamental research and application perspectives. The magnetic Weyl semimetal (WSM) state in the chiral antiferromagnet Mn$_3$Sn emerges with strong electronic correlations, offering an intriguing arena for exploring the interplay between Weyl fermions and correlation physics. One prominent characteristic of the WSM state is the chiral anomaly, yet the potential effects of electronic correlations on the chiral anomaly remain unexplored. Here, we report a comprehensive study of the in-plane magnetotransport properties of single-crystal Mn$_{3+x}$Sn$_{1-x}$ with three different Mn doping levels ($x=0.053$, 0.070, and 0.090). The excess Mn leads to glassy ferromagnetic behavior and the Kondo effect, aside from shifting the chemical potential relative to the Weyl nodes. Thus, systematic tuning of the Mn doping level enables us to study the interplay between the spin-fluctuation scatterings, the correlation effect, and the chiral anomaly. We identify negative longitudinal magnetoresistance and planar Hall effect specific to the chiral anomaly for all three doping levels, indicating that the chiral anomaly persists in the presence of strong correlations.