Surface Conductivity in Antiferromagnetic Semiconductor CrSb$_2$

TL;DR

This study investigates surface states in antiferromagnetic semiconductor CrSb₂, revealing temperature-independent surface conduction and metallic surface states confirmed by ARPES and calculations, despite the absence of topological band inversion.

Contribution

It provides evidence for trivial metallic surface states in CrSb₂, combining experimental and theoretical approaches to characterize surface conduction in an antiferromagnetic narrow-gap semiconductor.

Findings

Surface states are temperature independent.

ARPES shows electron-like pocket at Γ-Z.

First-principles confirm metallic surface states.

Abstract

The contribution of bulk and surface to the electrical resistance along crystallographic \textit{b}- and \textit{c}-axes as a function of crystal thickness gives evidence for a temperature independent surface states in an antiferromagnetic narrow-gap semiconductor CrSb$_{2}$. ARPES shows a clear electron-like pocket at $\Gamma$-$Z$ direction which is absent in the bulk band structure. First-principles calculations also confirm the existence of metallic surface states inside the bulk gap. Whereas combined experimental probes point to enhanced surface conduction similar to topological insulators, surface states are trivial since CrSb$_2$ exhibits no band inversion.