Propagation of a Laser-Induced Magnetostatic Wave Packet in a Pseudo Spin Valve in the Presence of Spin Pumping

Abstract

Spin pumping and angular momentum transfer, i.e., the emission of a spin current by a precessing magnetization and the reverse process of absorption, play an important role in coherent magnetic dynamics processes in multilayered structures. For ferromagnetic layers separated by a nonmagnetic interlayer these effects give rise to a dynamic coupling between the layers that is dissipative in nature and affects the damping of coherent magnetization precession. We have used micromagnetic simulations to analyze the influence of such a dynamic coupling on the propagation of a laser-induced surface magnetostatic wave (MSW) packet in a pseudo spin valve structure consisting of two ferromagnetic metallic layers separated by a nonmagnetic metallic interlayer. We have considered the MSW generation due to laser-induced heating, which leads to dynamic changes in magnetization and magnetic anisotropy, and added the dynamic coupling effect to the equations for our micromagnetic simulations. As a result, we have revealed that under certain conditions such a coupling leads to a decrease in the spatial damping of the wave packet that corresponds to the acoustic MSW mode forming in the structure considered.