Origin of magnetoresistance suppression in thin $\gamma$-MoTe$_2$

TL;DR

This study investigates how reducing the thickness of $ ext{MoTe}_2$ affects its large magnetoresistance, revealing that decreased mobility and increased electron-hole imbalance suppress XMR, with mobility playing a more significant role.

Contribution

The paper provides a detailed analysis of the thickness-dependent suppression of magnetoresistance in $ ext{MoTe}_2$, combining classical and quantum measurements to identify key contributing factors.

Findings

Magnetoresistance decreases with reduced thickness.

Carrier mobility decreases as thickness decreases.

Electron-hole imbalance increases with reduced thickness.

Abstract

We use both classical magnetotransport and quantum oscillation measurements to study the thickness evolution of the extremely large magnetoresistance (XMR) material and type-II Weyl semimetal candidate, $\gamma$-MoTe$_2$, protected from oxidation. We find that the magnetoresistance is systematically suppressed with reduced thickness. This occurs concomitantly with both a decrease in carrier mobility and increase in electron-hole imbalance. We model the two effects separately and conclude that the XMR effect is more sensitive to the former.