Spin and charge transport induced by gauge fields in a ferromagnet

Abstract

We present a microscopic theory of spin-dependent motive force ("spin motive force") induced by magnetization dynamics in a conducting ferromagnet, by taking account of spin relaxation of conduction electrons. The theory is developed by calculating spin and charge transport driven by two kinds of gauge fields; one is the ordinary electromagnetic field $A_{\mu }^{\mathrm{em}}$, and the other is the effective gauge field $A_{\mu }^z$ induced by dynamical magnetic texture. The latter acts in the spin channel and gives rise to a spin motive force. It is found that the current induced as a linear response to $A_{\mu }^z$ is not gauge-invariant in the presence of spin-flip processes. This fact is intimately related to the non-conservation of spin via Onsager reciprocity, so is robust, but indicates a theoretical inconsistency. This problem is resolved by considering the time dependence of spin-relaxation source terms in the "rotated frame", as in the previous study on Gilbert damping [J. Phys. Soc. Jpn. {\bf 76}, 063710 (2007)]. This effect restores the gauge invariance while keeping spin non-conservation. It also gives a dissipative spin motive force expected as a reciprocal to the dissipative spin torque ("$\beta$-term").

13 pages, 3 figures, submitted to PRB

References in corpus (11)

• Microscopic approach to current-driven domain wall dynamics
• Electrical detection of spin pumping due to the precessing magnetization of a single ferromagnet
• Microscopic Calculation of Spin Torques in Disordered Ferromagnets
• Electron Transport Driven by Nonequilibrium Magnetic Textures
• Spin pumping by a field-driven domain wall
• Functional Keldysh Theory of Spin Torques
• Spin Pumping of Current in Non-Uniform Conducting Magnets
• Voltage generation by ferromagnetic resonance
• Gauge Field Formulation of Adiabatic Spin Torques
• Inverse Spin Hall Effect Driven by Spin Motive Force
• Effect of spin diffusion on current generated by spin motive force

Cited by in corpus (14)

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• Spin correlation function theory of spin-charge conversion effects
• Spinmotive force with static and uniform magnetization induced by a time-varying electric field
• Rashba-induced spin electromagnetic fields in a strong sd coupling regime
• Microscopic calculation of thermally-induced spin-transfer torques
• Microscopic theory of magnon-drag electron flow in ferromagnetic metals
• Energetic perspective on emergent inductance exhibited by magnetic textures in the pinned regime
• Spin-motive force due to domain wall motion in the presence of Dzyaloshinskii-Moriya Interaction
• Stability of Spinmotive Force in Perpendicularly Magnetized Nanowires under High Magnetic Fields
• Variational approach to the stationary spin-Hall effect
• Coupling theory of emergent spin electromagnetic field and electromagnetic field
• Spin torque due to diffusive spin current in magnetic texture
• Stationary states and screening equations in the spin-Hall effect