Extreme magnetoresistance induced by Zeeman effect-driven electron-hole compensation and topological protection in MoSi$_2$

TL;DR

This study reveals that MoSi$_2$ exhibits extremely large, non-saturating magnetoresistance driven by Zeeman effect-induced electron-hole compensation and topological protection, with implications for advanced magnetic sensor applications.

Contribution

It demonstrates that Zeeman effect-driven electron-hole compensation and topological protection are key to the ultra-large magnetoresistance in MoSi$_2$, a novel insight into its electronic properties.

Findings

Magnetoresistance approaches 10^7% at 2 K and 14 T.

Electron-hole compensation evolves with magnetic field due to Zeeman effect.

Topological nature supported by Berry phase and carrier mobility.

Abstract

The magnetoresistance is the magnetic field induced change of electrical resistivity of a material. Recent studies have revealed extremely large magnetoresistance in several non-magnetic semimetals, which has been explained on the basis of either electron-hole compensation or the Fermi surface topology, or the combination of both. Here, we present a single crystal study on MoSi$_2$, which exhibits extremely large magnetoresistance, approaching almost 10$^7$ % at 2 K and 14 T magnetic field. It is found that the electron-hole compensation level in MoSi$_2$ evolves with magnetic field, which is resulted from strong Zeeman effect, and found beneficial in boosting the large non-saturating magnetoresistance. The non-trivial Berry phase in the de Haas-van Alphen oscillations and the moderate suppression of backward scattering of the charge carriers lend support for the topological nature of this semimetal. The ultra-large carrier mobility of the topologically protected charge carriers reinforces the magnetoresistance of MoSi2 to an unprecedented large value.