Topological Weyl semimetals in the chiral antiferromagnetic materials Mn3Ge and Mn3Sn

TL;DR

This paper predicts that Mn3Ge and Mn3Sn are antiferromagnetic Weyl semimetals with topological features like Weyl points and Fermi arcs, based on ab initio calculations, linking their anomalous Hall effect to topological properties.

Contribution

It demonstrates the existence of Weyl points and Fermi arcs in Mn3Ge and Mn3Sn, establishing a new principle for identifying magnetic Weyl semimetals via anomalous Hall effect.

Findings

Multiple Weyl points found in Mn3Ge and Mn3Sn

Fermi arcs observed on the surface of these materials

Chiral antiferromagnetism determines Weyl point positions

Abstract

Recent experiments revealed that Mn3Sn and Mn3Ge exhibit a strong anomalous Hall effect at room temperature, provoking us to explore their electronic structures for topological properties. By ab initio band structure calculations, we have observed the existence of multiple Weyl points in the bulk and corresponding Fermi arcs on the surface, predicting antiferromagnetic Weyl semimetals in Mn3Ge and Mn3Sn. Here the chiral antiferromagnetism in the Kagome-type lattice structure is essential to determine the positions and numbers of Weyl points. Our work further reveals a new guiding principle to search for magnetic Weyl semimetals among materials that exhibit a strong anomalous Hall effect.