Intrinsic torque on the orbital angular momentum in an electric field

Abstract

Orbitronics harnesses nonequilibrium densities and flows of electrons' orbital angular momentum (OAM). Although the OAM must be long lived to be useful in information processing, the mechanisms leading to OAM nonconservation remain unknown. Here we show that an electric field induces an intrinsic torque on the OAM mediated by the quantum metric tensor, without spin-orbit coupling or magnetic fields. The torque vanishes in pseudospin-1/2 systems with particle-hole symmetry but is nonzero in the presence of nontrivial textures. We discuss implications for topological materials and strategies for experimental observation.

Topics & Concepts