Prof. Urazhdin and collaborators solve the long-standing problem of nonlinear damping in magnetic films.
When the amplitude of oscillations in some dynamical systems become large, they start to experience nonlinear relaxation that suppresses large-amplitude dynamics. Among many manifestations of this adverse effect, it has prevented the development of efficient microwave oscillators based on magnetic materials. Until now, the mechanisms of nonlinear damping in magnetic films have not been established. In a paper, “Controlled nonlinear magnetic damping in spin-Hall nano-devices,” published in Nature Communications, Prof. Urazhdin and collaborators show that the nonlinear damping in magnetic films originates from non-resonant parametric pumping associated with ellipticity of magnetization precession, and demonstrate how it can be avoided to achieve large-amplitude magnetization oscillations.
Controlled nonlinear magnetic damping in spin-Hall nano-devices, Boris Divinsky, Sergei Urazhdin, Sergej O. Demokritov and Vladislav E. Demidov, Nature Comm. 10, 5211 (2019).