Spin currents and spin-orbit torques in ferromagnetic trilayers

Published

March 19, 2018

Author(s)

Seung-heon C. Baek, Vivek P. Amin, Young-Wan Oh, Gyungchoon Go, Seung-Jae Lee, Geun-Hee Lee, Kab-Jin Kim, Mark D. Stiles, Byong-Guk Park, Kyung Jin Lee

Abstract

Spin current generation by the spin-orbit interaction is one of the central themes in condensed matter physics. The spin Hall effect, for instance, is a bulk spin-orbit coupling effect that converts a charge current to a spin current. A recent theory predicted that interfaces can also generate a spin current, which results from spin-orbit scattering at the interface. This interface-generated spin current, which is distinctly different from the interface spin density generated by the Rashba-Edelstein effect, has not been identified experimentally. Here we demonstrate interface-generated spin currents at ferromagnet/normal metal interfaces. We find that the spin polarization of the interface-generated spin current has a component along the inversion asymmetry direction, which is absent for bulk spin-orbit coupling effects in heavy metals. This out-of-plane component of spin polarization enables field-free spin-orbit torque switching of perpendicular magnetization, which is of technological importance. The interface- generated spin current and associated spin-orbit torque will enable energy-efficient control of spintronic devices.

Citation

Nature Materials

Volume

17

Issue

6

Pub Type

Journals

Download Paper

https://doi.org/10.1038/s41563-018-0041-5

Local Download

Citation

Baek, S. , Amin, V. , Oh, Y. , Go, G. , Lee, S. , Lee, G. , Kim, K. , Stiles, M. , Park, B. and Lee, K. (2018), Spin currents and spin–orbit torques in ferromagnetic trilayers, Nature Materials, [online], https://doi.org/10.1038/s41563-018-0041-5, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923911 (Accessed November 4, 2025)