Non-equilibrium thermodynamic study of magnetization dynamics in the presence of spin-transfer torque

Abstract

The dynamics of magnetization in the presence of spin-transfer torque was studied. We derived the equation for the motion of magnetization in the presence of a spin current by using the local equilibrium assumption in non-equilibrium thermodynamics. We show that, in the resultant equation, the ratio of the Gilbert damping constant, $\alpha$, and the coefficient, $\beta$, of the current-induced torque, called non-adiabatic torque, depends on the relaxation time of the fluctuating field ${\tau }_c$. The equality $\alpha =\beta$ holds when ${\tau }_c$ is very short compared to the time scale of magnetization dynamics. We apply our theory to current-induced magnetization reversal in magnetic multilayers and show that the switching time is a decreasing function of ${\tau }_c$.

4 pages, 2 figures

References in corpus (13)

• Microwave Oscillations of a Nanomagnet Driven by a Spin-Polarized Current
• Current-driven Magnetization Reversal and Spin Wave Excitations in Co/Cu/Co Pillars
• Roles of non-equilibrium conduction electrons on magnetization dynamics of ferromagnets
• Micromagnetic understanding of current-driven domain wall motion in patterned nanowires
• Current-spin coupling for ferromagnetic domain walls in fine wires
• Spin Transfer Torque for Continuously Variable Magnetization
• Microscopic Calculation of Spin Torques in Disordered Ferromagnets
• Current-induced magnetization dynamics in disordered itinerant ferromagnets
• Theory of current-driven magnetization dynamics in inhomogeneous ferromagnets
• Identification of transverse spin currents in noncollinear magnetic structures
• Functional Keldysh Theory of Spin Torques
• Current-driven vortex domain wall dynamics by micromagnetic simulations
• Adiabatic Domain Wall Motion and Landau-Lifshitz Damping

Cited by in corpus (2)

• Spin-Currents and Spin-Pumping Forces for Spintronics
• Current-induced microwave excitation of a domain wall confined in a magnetic wire with bi-axial anisotropy