Weak Electronic Correlations Observed in Magnetic Weyl Semimetal Mn$_3$Ge

TL;DR

This study combines ARPES and DFT to analyze Mn3Ge's electronic structure, revealing metallic behavior, flat bands, and weaker electronic correlations compared to Mn3Sn, advancing understanding of its electronic properties.

Contribution

It provides the first systematic ARPES and DFT analysis of Mn3Ge's electronic structure, highlighting weaker correlations and detailed orbital contributions.

Findings

Mn3Ge exhibits metallic band crossing at the Fermi level.

Flat bands are observed along high symmetry directions.

Electronic correlations in Mn3Ge are weaker than in Mn3Sn.

Abstract

Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations, we systematically studied the electronic band structure of Mn$_3$Ge in the vicinity of the Fermi level. We observe several bands crossing the Fermi level, confirming the metallic nature of the studied system. We further observe several flat bands along various high symmetry directions, consistent with the DFT calculations. The calculated partial density of states (PDOS) suggests a dominant Mn $3d$ orbital contribution to the total valence band DOS. With the help of orbital-resolved band structure calculations, we qualitatively identify the orbital information of the experimentally obtained band dispersions. Out-of-plane electronic band dispersions are explored by measuring the ARPES data at various photon energies. Importantly, our study suggests relatively weaker electronic correlations in Mn$_3$Ge compared to Mn$_3$Sn.