Interface-generated orbital currents

Spin and orbital currents can be used in spintronic devices to electrically control the magnetic order of ferromagnets and antiferromagnets, providing an attractive write mechanism for magnetic memories. While electrical spin current generation, such as the spin Hall effect, has been extensively studied, orbital current generation is only beginning to be understood. Though a flurry of research is currently underway investigating the orbital Hall effect and its corresponding spin-orbit torques, little effort has been devoted to understanding orbital current generation at interfaces. Theoretical and experimental evidence already suggests that interfaces generate appreciable out-of-plane spin currents under an applied, in-plane electric field. To help fill in the gap in the study of orbital current generation, we present first principles transport calculations of a corresponding effect called of ‘interface-generated orbital currents.’ We calculate the strength and magnetization dependence of interface-generated orbital currents, which, unlike interface-generated spin currents, do not require spin-orbit coupling. Exploiting new sources of angular momentum transfer within magnetic heterostructures—such as interface-generated orbital currents—will help pave the way for more energy efficient magnetic memories.