Nonlinear enhancement of coherent magnetization dynamics

Elyasi, M.*; Yamamoto, Kei   ; Hioki, Tomosato*; Makiuchi, Takahiko*; Shimizu, Hiroki*; Saito, Eiji*; Bauer, G. E. W.*

Magnets are interesting materials for classical and quantum information technologies. However, the short decoherence and dephasing times that determine the scale and speed of information networks severely limit the appeal of employing the ferromagnetic resonance. Here we show that the lifetime and coherence of the uniform Kittel mode can be enhanced by three-magnon interaction-induced mixing with the long-lived magnons at the minima of the dispersion relation. Analytical and numerical calculations based on this model explain recent experimental results and predict experimental signatures of quantum coherence.