Unified First-Principles Study of Gilbert Damping, Spin-Flip Diffusion, and Resistivity in Transition Metal Alloys

Using a formulation of first-principles scattering theory that includes disorder and spin-orbit coupling on an equal footing, we calculate the resistivity ?, spin-flip diffusion length lsf, and Gilbert damping parameter ? for Ni1-xFex substitutional alloys as a function of x. For the technologically important Ni80Fe20 alloy, Permalloy, we...

Proximity-effect–assisted decay of spin currents in superconductors

The injection of pure spin current into superconductors by the dynamics of ferromagnetic contact is studied theoretically. Taking into account the suppression of the order parameter at the interfaces (inverse proximity effect) and the energy-dependence of spin-flip scattering, we determine the temperature-dependent ferromagnetic resonance...

Feedback control of noise in spin valves by the spin-transfer torque

The miniaturization of magnetic read heads and random access memory elements makes them vulnerable to thermal fluctuations. We demonstrate how current-induced spin-transfer torques can be used to suppress the effects of thermal fluctuations. This enhances the fidelity of perpendicular magnetic spin valves. The simplest realization is a dc to...

Magnetization dissipation in ferromagnets from scattering theory

The magnetization dynamics of ferromagnets is often formulated in terms of the Landau-Lifshitz-Gilbert (LLG) equation. The reactive part of this equation describes the response of the magnetization in terms of effective fields, whereas the dissipative part is parametrized by the Gilbert damping tensor. We formulate a scattering theory for the...

Manipulation of ferromagnets via the spin-selective optical Stark effect

We investigate the nonresonant all-optical switching of magnetization. We treat the inverse Faraday effect (IFE) theoretically in terms of the spin-selective optical Stark effect for linearly or circularly polarized light. In the dilute magnetic semiconductors (Ga,Mn)As, strong laser pulses below the band gap induce effective magnetic fields of...

Current-induced magnetization dynamics in two magnetic insulators separated by a normal metal

We study the dynamics of spin valves consisting of two layers of magnetic insulators separated by a normal metal in the macrospin model. A current through the spacer generates a spin Hall current that can actuate the magnetization via the spin-transfer torque. We derive expressions for the effective Gilbert damping and the critical currents for...