Work

Spin transport at interfaces with spin-orbit coupling: Phenomenology

Year: 2016

Type: article

Abstract: Most spintronic devices share two features: they utilize spin-orbit coupling and they contain interfaces. While bulk spin-orbit effects are thought to be well described by phenomenological theories, interfacial spin-orbit effects are not. A theory that could describe interfacial spin-orbit effects would be useful in analyzing experiments on heavy-metal ferromagnet bilayers, which are a key feature of potential energy-efficient implementations of MRAM. To develop such a theory, the authors present the boundary conditions needed for drift-diffusion models to treat interfaces with spin-orbit coupling. Together with the drift-diffusion equations, these boundary conditions give an analytical model of spin-orbit torques caused by both the spin Hall and Rashba-Edelstein effects. A key feature of these boundary conditions is that they capture spin currents generated by interfacial spin-orbit scattering. The authors validate this phenomenological approach by comparing the results with those obtained by solving the spin-dependent Boltzmann equation. They discuss the interpretation of current experiments, and describe in particular how interfacial effects give rise to torques on a nearby ferromagnetic layer even through a nonmagnetic spacer layer.

Source: Physical review. B./Physical review. B

DOI: 10.1103/physrevb.94.104420

Authors: V. P. Amin, M. D. Stiles

Institutions: National Institute of Standards and Technology, Center for Nanoscale Science and Technology, University of Maryland, College Park

Language: English

Topic: Magnetic properties of thin films

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Institute of Standards and Technology, Center for Nanoscale Science and Technology

Award: G8198481347