Direct evidence of electron-hole compensation for XMR in topologically trivial YBi

TL;DR

This study provides direct evidence that electron-hole compensation, rather than topological electronic structures, is responsible for the extreme magnetoresistance observed in the topologically trivial compound YBi.

Contribution

The paper presents combined experimental and theoretical evidence showing YBi is topologically trivial and exhibits perfect electron-hole compensation, clarifying the origin of XMR in this material.

Findings

YBi is topologically trivial with no band inversion.

Perfect electron-hole compensation observed in YBi.

Electron-hole compensation likely causes XMR in YBi.

Abstract

The prediction of topological states in rare earth monopnictide compounds has attracted renewed interest. Extreme magnetoresistance (XMR) has also been observed in several nonmagnetic rare earth monopnictide compounds. The origin of XMR in these compounds could be attributed to several mechanisms, such as topologically nontrivial electronic structures and electron-hole carrier balance. YBi is a typical rare earth monopnictide exhibiting XMR, and expected to have a nontrivial electronic structure. In this work, we performed a direct investigation of the electronic structure of YBi by combining angle resolved photoemission spectroscopy and theoretical calculations. Our results show that YBi is topologically trivial without the expected band inversion, and they rule out the topological effect as the cause of XMR in YBi. Furthermore, we directly observed perfect electron-hole compensation in the electronic structure of YBi, which could be the primary mechanism accounting for the XMR.