Intrinsic nonlinear ferromagnetic relaxation (invited)

The intrinsic damping mechanism arising from the magnon–magnon scattering is theoretically studied in three dimensional and two dimensional ferromagnets. We develop an analytic theory, which identifies the three-magnon (in bulk) and four-magnon (in thin films) scattering processes, responsible for rapid relaxation. Micromagnetic simulations are used to confirm the analytic theory predictions, and to investigate the damping in different realistic technologically important systems. For the large angle rotation of magnetization, this intrinsic mechanism can dominate competing linear mechanisms even for rapidly relaxing metals.