# Gate-Defined One-Dimensional Channel and Broken Symmetry States in MoS$_2$ van der Waals Heterostructures

## TL;DR

This study demonstrates high-mobility trilayer MoS₂ devices with gate-defined channels showing quantum oscillations and conductance plateaus, revealing broken symmetry states and valley Zeeman effects in van der Waals heterostructures.

## Contribution

It introduces a method to create gate-defined one-dimensional channels in MoS₂ heterostructures and observes quantum phenomena related to broken symmetry states.

## Key findings

- High electron mobility of 7000 cm²/(V s) at low temperature
- Observation of Shubnikov--de Haas oscillations at low magnetic fields
- Formation of gate-tunable channels with conductance plateaus

## Abstract

We have realized encapsulated trilayer MoS$_2$ devices with gated graphene contacts. In the bulk, we observe an electron mobility as high as 7000~cm$^{2}$/(V s) at a density of 3 $\times$ 10$^{12}$~cm$^{-2}$ at a temperature of 1.9~K. Shubnikov--de Haas oscillations start at magnetic fields as low as 0.9~T. The observed 3-fold Landau level degeneracy can be understood based on the valley Zeeman effect. Negatively biased split gate electrodes allow us to form a channel that can be completely pinched off for sufficiently large gate voltages. The measured conductance displays plateau-like features.