Nonlinear spin-wave scattering in a micro-structured magnonic crystal

We study the nonlinear multi-magnon processes in a micro-structured magnonic crystal consisting of a Ni81Fe19 waveguide, which has been periodically modulated in its saturation magnetization by localized ion implantation. A significant modification of the nonlinear magnon spectrum compared to a reference waveguide is determined, exhibiting a predominant scattering into modes with a frequency at the magnonic band gaps and an enhancement of the nonlinearities for some excitation frequencies. The results prove the feasibility to utilize nonlinear multi-magnon scattering for magnon spintronic applications on the micrometer scale.