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 currents 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.

Accepted for publication in Physical Review Letters

References in corpus (8)

• Spin Transfer Torques
• Theory of spin Hall magnetoresistance
• Matching domain wall configuration and spin-orbit torques for very efficient domain-wall motion
• Non-collinear Magnetoelectronics
• Determination of intrinsic spin Hall angle in Pt
• Angular and temperature dependence of current induced spin-orbit effective fields in Ta/CoFeB/MgO nanowires
• Interface enhancement of Gilbert damping from first-principles
• Current-induced motion of a transverse magnetic domain wall in the presence of spin Hall effect

Cited by in corpus (5)

• Tuning interfacial spins in antiferromagnetic / ferromagnetic / heavy metal heterostructures via spin-orbit torque
• Noncollinear Spintronics and Electric-Field Control: A Review
• Spin transparency for an interface of an ultrathin magnet within the spin dephasing length
• Static and Dynamic Magnetic Properties of FeMn/Pt Multilayers
• Influences of interfacial oxidization on surface magnetic energy, magnetic damping and spin-orbit-torques in Pt / ferromagnet / capping structures