Dominance of Extrinsic Scattering Mechanisms in the Orbital Hall Effect: Graphene, Transition Metal Dichalcogenides, and Topological Antiferromagnets

The theory of the orbital Hall effect (OHE), a transverse flow of orbital angular momentum (OAM) in response to an electric field, has concentrated on intrinsic mechanisms.Here, using a quantum kinetic formulation, we determine the full OHE in the presence of short-range disorder using 2D massive Dirac fermions as a prototype.We find that, in doped systems, extrinsic effects associated with the Fermi surface (skew scattering and side jump) provide ≈ 95% of the OHE.This suggests that, at experimentally relevant transport densities, the OHE is primarily extrinsic.