Large spin hall conductivity in low-symmetry semiconductor ZrSe3

Spin-orbit torques (SOTs) in two-dimensional (2D) transition-metal dichalcogenides (TMDs) based on magnetic heterostructures have drawn extensive attentions owning to their potential applications in spintronic devices. Here, we investigated the current-induced SOTs in ZrSe3, which is a 2D van der Waals semiconductor characterized by both strong spin-orbit coupling and broken crystal symmetry. A large SOT efficiency along with an out-of-plane damping-like torque is achieved, when the charge current is applied along the low symmetry crystal axis of ZrSe3. Significantly, the SOT efficiency we detected from ZrSe3 (7.6 nm)/ Py(10 nm) device is up to 2.67, corresponding to a large spin Hall conductivity of 377.1 × 103ℏ/2e (Ω·m)−1. Such a large spin Hall conductivity is superior to most of the conventional heavy metals, TMDs and topological insulators. Thickness dependence study further demonstrates the main contribution to the large SOTs is bulk spin Hall effect in ZrSe3. Combining the notable out-of-plane damping-like SOT with high spin Hall conductivity, our study provides a new strategy for low-power SOT devices based on 2D semiconductors.