A unified drift-diffusion theory for transverse spin currents in spin valves, domain walls and other textured magnets

Abstract

Spins transverse to the magnetization of a ferromagnet only survives over a short distance. We develop a drift-diffusion approach that captures the main features of transverse spin effects in systems with arbitrary spin textures (vortices, domain walls) and generalizes the Valet-Fert theory. In addition to the standard characteristic lengths (mean free path for majority and manority electrons, spin diffusion length), the theory introduces two lengths scales, the transverse spin coherence length and the (Larmor) spin precession length. We show how those lengths can be extracted from ab-initio calculations or measured with giant magneto-resistance experiments. In long (adiabatic) domain walls, we provide an analytic formula that expresses the so called "non-adiabatic" (or field like) torque in term of those lengths scales. However, this "non adiabatic" torque is no longer a simple material parameter and depends on the actual spin texture: in thin (< 10nm) domain walls, we observe very significant deviations from the adiabatic limit.

References in corpus (5)

• Microscopic approach to current-driven domain wall dynamics
• Non-collinear Magnetoelectronics
• Spin-torque driven ferromagnetic resonance in a nonlinear regime
• Spin torque and waviness in magnetic multilayers: a bridge between Valet-Fert theory and quantum approaches
• Multiscale approach to spin transport in magnetic multilayers

Cited by in corpus (17)

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• Analytical description of ballistic spin currents and torques in magnetic tunnel junctions
• Nonlocal Spin Dynamics in the Crossover from Diffusive to Ballistic Transport
• Experimental Evidence of Non-Negligible Imaginary Part of Spin Mixing Conductance and Its Impact on Magnetization Dynamics in Heavy-Metal|Ferromagnet Bilayers
• Role of an additional interfacial spin-transfer torque for current-driven skyrmion dynamics in chiral magnetic layers
• Measurement of the Spin Absorption Anisotropy in Lateral Spin Valves
• Control of the Oscillatory Interlayer Exchange Interaction with Terahertz Radiation
• Characterization of spin relaxation anisotropy in Co using spin pumping
• Effect of capping layer on spin-orbit torques
• Nonequilibrium dynamics in a spin valve with noncollinear magnetization
• Self-Consistent Computation of Spin Torques and Magneto-Resistance in Tunnel Junctions and Magnetic Read-Heads with Metallic Pinhole Defects
• Micromagnetic simulations of spin-torque driven magnetisation dynamics with spatially resolved spin transport and magnetisation texture
• Sustained RF oscillations from thermally induced spin-transfer torque
• Measuring the magnetic anisotropy of the spin Hall effect and spin relaxation length in nickel and permalloy via electrical spin injection