Damping and magnetic uniaxial anisotropy dependence of transient spin waves and mode type in magnetic nanowires

Abstract

Patterned nanowires could enable tunable spin wave filters, logic and frequency multiplier devices. Using micromagnetic models, we investigate the effect of Gilbert damping and uniaxial anisotropy constant (K1) on the supported spin wave mode types, spatial and temporal transmission profile for a fixed finite patterned nanowire geometry under external DC and RF magnetic fields. Increasing damping constant leads to a shorter mode propagation length due to higher loss and flipping of the spin wave mode due to precession instability. Increasing K1 from -10-5 to 105 J·m-3also flips the mode and extends precession times. We further study the effect of changing the sample's initial magnetization orientation on the temporal and spectral responses. Anisotropy and damping engineering in patterned nanostructures could help build controlled spin wave filters, mode converters and multipliers.