Direct Observation of Valley Coupled Topological Current in MoS$_2$

TL;DR

This paper demonstrates electrical generation and detection of valley currents in monolayer MoS2 via the valley Hall effects, revealing long-range valley transport at room temperature, advancing valleytronics technology.

Contribution

It provides the first electrical evidence of valley current generation and detection in MoS2 without optical methods, enabling practical valleytronic devices.

Findings

Valley current can be electrically induced and detected in MoS2.

Long-range valley transport observed at room temperature.

Valley Hall and inverse valley Hall effects demonstrated.

Abstract

The valley degree of freedom of electrons in two-dimensional transition metal dichalcogenides has been extensively studied by theory, optical and optoelectronic experiments. However, generation and detection of pure valley current without relying on optical selection have not yet been demonstrated in these materials. Here, we report that valley current can be electrically induced and detected through the valley Hall effect and inverse valley Hall effect, respectively, in monolayer molybdenum disulfide. Specifically, long-range valley transport is observed over half a micron distance at room temperature. Our findings will enable a new generation of electronic devices utilizing the valley degree of freedom, which can be used for future novel valleytronic applications.