Evaluating the locality of intrinsic precession damping in transition metals

Abstract

The Landau-Lifshitz-Gilbert damping parameter is typically assumed to be a local quantity, independent of magnetic configuration. To test the validity of this assumption we calculate the precession damping rate of small amplitude non-uniform mode magnons in iron, cobalt, and nickel. At scattering rates expected near and above room temperature, little change in the damping rate is found as the magnon wavelength is decreased from infinity to a length shorter than features probed in recent experiments. This result indicates that non-local effects due to the presence of weakly non-uniform modes, expected in real devices, should not appreciably affect the dynamic response of the element at typical operating temperatures. Conversely, at scattering rates expected in very pure samples around cryogenic temperatures, non-local effects result in an order of magnitude decrease in damping rates for magnons with wavelengths commensurate with domain wall widths. While this low temperature result is likely of little practical importance, it provides an experimentally testable prediction of the non-local contribution of the spin-orbit torque-correlation model of precession damping. None of these results exhibit strong dependence on the magnon propagation direction.

Accepted to Phys. Rev. B Brief Reports

References in corpus (6)

• Enhanced Gilbert Damping in Thin Ferromagnetic Films
• Identification of the dominant precession damping mechanism in Fe, Co, and Ni by first-principles calculations
• First-principles study of magnetization relaxation enhancement and spin-transfer in thin magnetic films
• Spin orbit precession damping in transition metal ferromagnets
• Magnetization relaxation in (Ga,Mn)As ferromagnetic semiconductors
• Current-induced noise and damping in non-uniform ferromagnets

Cited by in corpus (6)

• Mode- and size-dependent Landau-Lifshitz damping in magnetic nanostructures: Evidence for non-local damping
• Non-local Gilbert damping tensor within the torque-torque correlation model
• Magnetic damping anisotropy in the two-dimensional van der Waals material Fe${}_3$GeTe${}_2$ from first principles
• Hole spin relaxation and coefficients in Landau-Lifshitz-Gilbert equation in ferromagnetic GaMnAs
• Real-space nonlocal Gilbert damping from exchange torque correlation applied to bulk ferromagnets and their surfaces
• Theoretical determination of Gilbert damping in reduced dimensions