Significant Chiral Magnetotransport Magnified by Multiple Weyl Nodes

TL;DR

This paper investigates the magnetotransport properties of NdAlSi, a magnetic Weyl semimetal with multiple Weyl nodes, revealing significant negative magnetoresistance and an exotic anomalous Hall effect driven by topological and magnetic interplay.

Contribution

It demonstrates the large chiral anomaly coefficient and unique Hall behavior in NdAlSi, highlighting its potential for studying magnetic Weyl semimetals.

Findings

Large negative magnetoresistance attributed to chiral anomaly

Chiral coefficient exceeds that of many other topological materials

Exotic anomalous Hall effect with out-of-sync behavior

Abstract

The intertwining of magnetism with topology is known to give rise to exotic quantum phenomena. Here, we explore the magnetotransport properties of NdAlSi, a magnetic Weyl semimetal that spontaneously breaks inversion and time-reversal symmetries and hosts a large number of Weyl nodes. We observe a significant negative magnetoresistance, which we attribute to the chiral anomaly associated with multiple Weyl nodes. Remarkably, the extracted chiral coefficient reaches approximately $52~\mathrm{m\Omega}^{-1}~\mathrm{m}^{-1}~\mathrm{T}^{-2}$, larger than many other topological materials. Additionally, we observe an exotic anomalous Hall effect with an out-of-sync behavior, where the anomalous Hall resistance does not exactly follow the field dependence of the magnetization, in contrast to that in conventional ferromagnets. These rich quantum transport phenomena, driven by the interplay between magnetism and Weyl nodes, establish NdAlSi as a prime platform for exploring the intricate topological behaviors of magnetic Weyl semimetals.