Modelling Studies of Magnetostatic Modes in Hybrid MW-YIG Structures

Studies on spin waves (magnons) formed by collective electron spin excitations in magnetic materials have recently gained importance due to their great potential for magnonics and hybrid quantum systems. In this study, the magnetostatic spin-wave modes excited as a result of the coupling between the 2D microwave resonator and the YIG sphere have been investigated computationally. The simulations have been performed using commercial finite element method software (CST Studio Suite). The 2D microwave resonator is realized on the ground plane of the broadband microstrip structure by using a low-loss printed circuit board. The calculations reveal the Q factor to be about 300 by optimizing the resonance frequency to 7 GHz. The most interesting result of simulations is the observation that the magneto-static spin-wave modes of the YIG sphere may be excited depending on the geometry of the hybrid structure. A strong interaction between the YIG and the microwave resonator observed in the dispersion curves of these modes reveals the realization of the strong coupling regime, which is a prerequisite of their use in quantum hybrid devices.