Observation of two-dimensional Fermi surface and Dirac dispersion in YbMnSb$_2$

TL;DR

This study reports the discovery of a two-dimensional Dirac semimetal state in YbMnSb$_2$, characterized by a 2D Fermi surface and Dirac dispersion, with implications for magnetic Dirac physics.

Contribution

It provides experimental evidence of Dirac dispersion and a 2D Fermi surface in YbMnSb$_2$, aligning with theoretical predictions and highlighting its potential for magnetic Dirac physics research.

Findings

YbMnSb$_2$ is a low-carrier-density semimetal.

The material exhibits a 2D Fermi surface with Dirac dispersion.

Low-temperature resistivity indicates high scattering efficiency.

Abstract

We present the crystal structure, electronic structure, and transport properties of the material YbMnSb$_2$, a candidate system for the investigation of Dirac physics in the presence of magnetic order. Our measurements reveal that this system is a low-carrier-density semimetal with a 2D Fermi surface arising from a Dirac dispersion, consistent with the predictions of density functional theory calculations of the antiferromagnetic system. The low temperature resistivity is very large, suggesting scattering in this system is highly efficient at dissipating momentum despite its Dirac-like nature.