Observations of Deterministic Chaos of Parallel-Pumped Magnons in Ferromagnetic (CH₃NH₃)₂CuCl₄

Abstract

Parallel pumping experiments in ferromagnetic (CH₃NH₃)₂CuCl₄ are studied at the pumping frequency of 9.39 GHz and the temperature of 1.65 K. Above the spin-wave instability threshold, auto-oscillations of magnon amplitude with a frequency of 8 kHz are observed. As the pumping power is increased, period-doubling, chaos and periodic windows are observed. Phase space portraits and one-dimensional return maps are constructed from the time series data.