Skew Scattering in Graphene with Proximity Spin-Orbital Effects

The generation of spin currents in nonmagnetic materials via purely electrical means has fascinated scientists since the first experimental reports of spin Hall effect (SHE) a decade ago. The SHE finds its origin in the rich charge-spin-coupled dynamics triggered by strong spin–orbit interactions. While the SHE has been detected univocally in metals and semiconductors, the design of nanostructures allowing the electrostatic control of spin Hall currents remains a big challenge. In this work, we theoretically show that skew scattering is ubiquitous in graphene-based heterostructures where mirror reflection and sublattice symmetry are simultaneously broken. Unlike conventional skew scattering-driven SHE, which requires spin–orbit-active or magnetic impurities, the skewness mechanism unveiled here results from the out-of-plane tilting of the eigenstates’ spin texture and thus it manifests for generic impurity disorder. Our results open realistic prospects for the all-electrical control of spin currents in van der Waals heterostructures of much current interest.