title: Enhanced Spin-Orbit Torque via Modulation of Spin Current Absorption.
abstract: The magnitude of spin-orbit torque (SOT), exerted to a ferromagnet (FM) from an adjacent heavy metal (HM), strongly depends on the amount of spin current absorbed in the FM. We exploit the large spin absorption at the Ru interface to manipulate the SOTs in HM/FM/Ru multilayers. While the FM thickness is smaller than its spin dephasing length of 1.2 nm, the top Ru layer largely boosts the absorption of spin currents into the FM layer and substantially enhances the strength of SOT acting on the FM. Spin-pumping experiments induced by ferromagnetic resonance support our conclusions that the observed increase in the SOT efficiency can be attributed to an enhancement of the spin-current absorption. A theoretical model that considers both reflected and transmitted mixing conductances at the two interfaces of FM is developed to explain the results.
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.|Shanghai Key Laboratory of Special Artificial Microstructure Materials & School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Xuepeng
authors.initials: X
authors.lastname: Qiu
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.
authors.forename: William
authors.initials: W
authors.lastname: Legrand
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Pan
authors.initials: P
authors.lastname: He
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Rajagopalan
authors.initials: R
authors.lastname: Ramaswamy
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia.
authors.forename: Aurelien
authors.initials: A
authors.lastname: Manchon
authors.affiliation: Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: Yang