Nonlinear Fano resonance in a coupled system magnonic microwave-guide - resonator

The purpose of research is to study of characteristics of the Fano resonance in a coupled system of nonlinear microwave-guides and resonators depending on geometric parameters of the systems, magnitude of the coupling between them, and the intensity of spin waves. Methods. Linear and nonlinear spin-wave excitations in lateral systems of irregular microwaveguides and resonators based on films of yttrium iron garnet are considered. Using micromagnetic simulation of spin-wave excitations and numerical integration of the coupled wave equation system, the transfer characteristics of the "microwaveguide - resonator" system and the Fano resonance parameters are calculated taking into account the cubic nonlinearity of magnetic media. Results. Based on the numerical integration of the system of equations of coupled waves that take into account the cubic nonlinearity of the magnetic media, theoretical studies have been carried out of the dependences of the transfer and phase characteristics of the "microwave-guide - resonator" system on the intensity of surface spin waves. Features of the demonstration of constructive and destructive interference of spin waves at Fano resonance are studied. Dependences of characteristics of the parameters of the Fano nonlinear resonance (asymmetry coefficient, resonance frequency shifts) on the intensity of spin-wave excitations are established. Conclusion. Results can be used to create spin-wave demultiplexers, power dividers and microwave couplers based on the lateral system of magnetic waveguides as a threshold element for neuromorphic networks, etc.