Observation of gapped state in rare-earth monopnictide HoSb

TL;DR

This study investigates the electronic structure of HoSb, revealing a gapped state without band inversion, and suggests that electron-hole compensation drives its extreme magnetoresistance.

Contribution

The paper provides the first detailed ARPES and magnetotransport analysis of HoSb, showing it has a gapped state without topological surface states and highlighting electron-hole compensation as key to its XMR.

Findings

HoSb has bulk band gaps at G and X points without band inversion.

HoSb is a nearly electron-hole compensated semimetal.

Electron-hole compensation likely causes non-saturating XMR.

Abstract

The rare-earth monopnictide family is attracting an intense current interest driven by its unusual extreme magnetoresistance (XMR) property and the potential presence of topologically non-trivial surface states. The experimental observation of non-trivial surface states in this family of materials are not ubiquitous. Here, using high-resolution angle-resolved photoemission spectroscopy (ARPES), magnetotransport, and parallel first-principles modeling, we examine the nature of electronic states in HoSb. Although we find the presence of bulk band gaps at the G and X-symmetry points of the Brillouin zone (BZ), we do not find these gaps to exhibit band inversion so that HoSb does not host a Dirac semimetal state. Our magnetotransport measurements indicate that HoSb can be characterized as a correlated nearly-complete electron-hole-compensated semimetal. Our analysis reveals that the nearly perfect electron-hole compensation could drive the appearance of non-saturating XMR effect in HoSb.