We theoretically investigate spin-orbit torques in insulator/ferromagnet/normal-metal structures with a focus on interfacial spin-orbit coupling effect at an insulator/ferromagnet interface. Based on the spin drift-diffusion formalism generalized to consider transverse spin currents in a ferromagnet and the boundary condition to consider transverse spin currents leaving from a ferromagnet, we find that interfacial spin-orbit coupling at the insulator/ferromagnet interface contributes to dampinglike spin-orbit torque, which is important for current-driven magnetization dynamics, even when the interfacial spin-orbit coupling generates the only fieldlike component. We also calculate spin-orbit torques in a single ferromagnet sandwiched by two dissimilar insulators, which provides additional information about interfacial spin-orbit interaction at insulator/ferromagnet interfaces.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (Grants No. 2020R1C1C1012664, No. 2019M3F3A1A02071509, No. 2020R1A2C3013302, and No. 2020M3F3A2A01082591), the KIST Institutional Program (Grant No. 2E31032), the National Research Council of Science and Technology (NST) (Grant No. CAP-16-01-KIST), and Samsung Electronics Co., Ltd. (Grant No. IO201019-07699-01).
© 2021 American Physical Society.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics