Control of magnetization in magnetic nanostructures is essential for development of spintronic devices because it governs fundamental device characteristics such as energy consumption, areal density, and operation speed. In this respect, spin–orbit torque (SOT), which originates from the spin–orbit interaction, has been widely investigated due to its efficient manipulation of the magnetization using in-plane current. SOT spearheads novel spintronic applications including high-speed magnetic memories, reconfigurable logics, and neuromorphic computing. Herein, recent advances in SOT research, highlighting the considerable benefits and challenges of SOT-based spintronic devices, are reviewed. First, the materials and structural engineering that enhances SOT efficiency are discussed. Then major experimental results for field-free SOT switching of perpendicular magnetization are summarized, which includes the introduction of an internal effective magnetic field and the generation of a distinct spin current with out-of-plane spin polarization. Finally, advanced SOT functionalities are presented, focusing on the demonstration of reconfigurable and complementary operation in spin logic devices.
Bibliographical noteFunding Information:
J.R. and S.L. contributed equally to this work. This work was supported by the National Research Foundation of Korea (NRF-2015M3D1A1070465, 2017R1A2A2A05069760, 2017M2A2A6A01071238), the Basic Research Laboratory Program (2018 R1A4A1020696).
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- spin currents
- spin logic devices
- spintronic applications
- spin–orbit torques
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering