Spin-orbit coupling induced valley Hall effects in transition-metal dichalcogenides

TL;DR

This paper demonstrates that in transition-metal dichalcogenides, the coexistence of Ising and Rashba spin-orbit couplings induces a tunable valley Hall effect, observable via gate-dependent valley Hall conductivity and Kerr effect measurements.

Contribution

It reveals a new type of valley Hall effect driven by spin-orbit couplings, with tunability near the conduction band edge, expanding understanding of spin-valley physics in 2D materials.

Findings

Spin-orbit couplings create a valley Hall effect in transition-metal dichalcogenides.

The effect is highly tunable by external gates near the conduction band edge.

Gate-dependent valley Hall conductivity can be detected via Kerr effect experiments.

Abstract

In transition-metal dichalcogenides, electrons in the K-valleys can experience both Ising and Rashba spin-orbit couplings. In this work, we show that the coexistence of Ising and Rashba spin-orbit couplings leads to a special type of valley Hall effect, which we call spin-orbit coupling induced valley Hall effect. Importantly, near the conduction band edge, the valley-dependent Berry curvatures generated by spin-orbit couplings are highly tunable by external gates and dominate over the intrinsic Berry curvatures originating from orbital degrees of freedom under accessible experimental conditions. We show that the spin-orbit coupling induced valley Hall effect is manifested in the gate dependence of the valley Hall conductivity, which can be detected by Kerr effect experiments.