Density-dependent spin susceptibility and effective mass in monolayer MoSe2

TL;DR

This study investigates the quantum properties of monolayer MoSe2, revealing enhanced spin susceptibility and effective mass variations due to electron interactions, using a novel triple-gate device with high mobility.

Contribution

It introduces a triple-gate device with bismuth contacts for reliable low-density measurements and demonstrates interaction effects on spin and mass in monolayer MoSe2.

Findings

High Hall mobility (~22,000 cm2/Vs) achieved at low densities

Observation of metal-insulator transitions and quantum oscillations

Enhanced spin susceptibility and density-dependent effective mass

Abstract

Atomically thin MoSe2 is a promising platform for investigating quantum phenomena due to its large effective mass, high crystal quality, and strong spin-orbit coupling. In this work, we demonstrate a triple-gate device design with bismuth contacts, enabling reliable ohmic contact down to low electron densities, with a maximum Hall mobility of approximately 22,000 cm2/Vs. Low-temperature transport measurements illustrate metal-insulator transitions, and density-dependent quantum oscillation sequences. Enhanced spin susceptibility and density-dependent effective mass are observed, attributed to interaction effects and valley polarization. These findings establish monolayer MoSe2 as a versatile platform for further exploring interaction-driven quantum states.