Minimal Model of Spin-Transfer Torque and Spin Pumping caused by Spin Hall Effect

Abstract

In the normal metal/ferromagnetic insulator bilayer (such as Pt/Y${}_3$Fe${}_5$O${}_{12}$) and the normal metal/ferromagnetic metal/oxide trilayer (such as Pt/Co/AlO${}_x$) where spin injection and ejection are achieved by the spin Hall effect in the normal metal, we propose a minimal model based on quantum tunneling of spins to explain the spin-transfer torque and spin pumping caused by the spin Hall effect. The ratio of their damping-like to field-like component depends on the tunneling wave function that is strongly influenced by generic material properties such as interface $s-d$ coupling, insulating gap, and layer thickness, yet the spin relaxation plays a minor role. The quantified result renders our minimal model an inexpensive tool for searching for appropriate materials.

References in corpus (1)

• Theory of spin Hall magnetoresistance

Cited by in corpus (14)

• Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems
• Long-distance spin transport in a disordered magnetic insulator
• Bulk and surface spin conductivity in topological insulators with hexagonal warping
• Voltage Controlled Spin-Orbit Torque Switching in W/CoFeB/MgO
• Anisotropic superconducting spin transport at magnetic interfaces
• Current direction anisotropy of the spin Hall magnetoresistance in nickel ferrite thin films with bulk-like magnetic properties
• Spin Hall Effect Induced Spin Transfer Through an Insulator
• Edelstein and inverse Edelstein effects caused by the pristine surface states of topological insulators
• Understanding current-driven dynamics of magnetic Néel walls in heavy metal/ferromagnetic metal/oxide trilayers
• Spin torque and persistent currents caused by percolation of topological surface states
• Persistent currents and spin torque caused by percolated quantum spin Hall state
• Theory of in-plane current induced spin torque in metal/ferromagnet bilayers
• Dynamic spin-charge coupling: spin Hall magnetoresistance in non-magnetic conductors
• Effect of Quantum Tunneling on Spin Hall Magnetoresistance