Spin Valley Hall Effects in Transition-metal Dichalcogenides

In gated transition-metal dichalcogenides (TMDs), electrons near the K-valleys experience both Ising spin-orbit coupling (SOC) due to the intrinsic noncentrosymmetric lattice symmetry and Rashba SOC due to gating. In this work, we show that the coexistence of Ising and Rashba SOCs leads to a new type of valley Hall effect, which we call spin valley Hall effect. Importantly, near the conduction band edge of TMDs, the valley-dependent Berry curvatures due to SOCs are highly tunable by external gates and dominate over the intrinsic Berry curvatures. We show that the spin valley Hall effect can be manifested in the gate dependence of the valley Hall conductivity, which can be detected by Kerr effect experiments.