Deficiency of the bulk spin Hall effect model for spin-orbit torques in magnetic-insulator/heavy-metal heterostructures

• DOI: 10.1103/physrevb.95.241305
• Publication Date: 2017-06-23T22:08:57Z
• Authors: Junxue Li; Guoqiang Yu; Chi Tang; Yizhou Liu; Zhong Shi; Yawen Liu; Aryan Navabi; Mohammed Aldosary; Qiming Shao; Kang L. Wang; Roger Lake; Jing Shi
• Keywords: Ferrimagnetism

Electrical currents in a magnetic-insulator/heavy-metal heterostructure can induce two simultaneous effects, namely, spin Hall magnetoresistance (SMR) on the heavy-metal side and spin-orbit torques (SOTs) magnetic-insulator side. Within framework of pure current model based bulk effect (SHE), ratio Hall-induced anomalous (SH-AHE) to SMR should be equal fieldlike torque (FLT) dampinglike (DLT). We perform quantitative study SMR, SH-AHE, SOTs series thulium iron garnet/platinum or $\mathrm{T}{\mathrm{m}}_{3}\mathrm{F}{\mathrm{e}}_{5}{\mathrm{O}}_{12}/\mathrm{Pt}$ heterostructures with different $\mathrm{T}{\mathrm{m}}_{3}\mathrm{F}{\mathrm{e}}_{5}{\mathrm{O}}_{12}$ thicknesses, where is ferrimagnetic insulator perpendicular magnetic anisotropy. find between measured effective fields FLT DLT at least times larger than SH-AHE SMR. In addition, SHE grossly underestimates spin-torque efficiency FLT. Our results reveal deficiencies also address importance interfacial effects such as Rashba proximity heterostructures.