Thermal instability in a ferrimagnetic resonator strongly coupled to a loop-gap microwave cavity

We study the nonlinear response of a ferrimagnetic sphere resonator (FSR) strongly coupled to a microwave loop-gap resonator (LGR). The measured response in the regime of weak nonlinearity allows the extraction of the FSR Kerr coefficient and its cubic damping rate. We find that there is a certain range of driving parameters in which the system exhibits instability. In that range, self-sustained modulation of the reflected power off the system is generated. The instability is attributed to absorption-induced heating of the FSR above its Curie temperature.

Automated summary

In this study, we investigated the nonlinear response of a ferrimagnetic sphere resonator strongly coupled to a microwave loop-gap resonator, and found that the system exhibits instability within a certain range of driving parameters, leading to self-sustained modulation of the reflected power. This instability is attributed to absorption-induced heating of the ferrimagnetic sphere resonator above its Curie temperature.