Magnetic Weyl Semimetal Phase in a Kagome Crystal

TL;DR

This paper experimentally demonstrates that the ferromagnetic crystal Co3Sn2S2 is a magnetic Weyl semimetal, revealing its surface Fermi-arcs and bulk band structure, which could enable novel topological phenomena.

Contribution

It provides the first direct visualization of the electronic structure of a magnetic Weyl semimetal using ARPES, confirming Co3Sn2S2 as a magnetic Weyl semimetal.

Findings

Visualization of surface Fermi-arcs in Co3Sn2S2

Observation of linear bulk band dispersions across Weyl points

Establishment of Co3Sn2S2 as a magnetic Weyl semimetal

Abstract

Weyl semimetals are crystalline solids that host emergent relativistic Weyl fermions and have characteristic surface Fermi-arcs in their electronic structure. Weyl semimetals with broken time reversal symmetry are difficult to identify unambiguously. In this work, using angle-resolved photoemission spectroscopy, we visualized the electronic structure of the ferromagnetic crystal Co3Sn2S2 and discovered its characteristic surface Fermi-arcs and linear bulk band dispersions across the Weyl points. These results establish Co3Sn2S2 as a magnetic Weyl semimetal that may serve as a platform for realizing phenomena such as chiral magnetic effects, unusually large anomalous Hall effect and quantum anomalous Hall effect.