Hybrid Photon‐Magnon Systems: Exploring the Purcell Effect

ABSTRACT We present a novel approach to observing the Purcell effect in a photon–magnon coupled (PMC) hybrid system comprising a yttrium iron garnet (YIG) thin film and a hexagonal ring resonator (HRR) in a planar geometry. Using CST Microwave Studio, we simulated the system for varying YIG damping constants while keeping HRR properties fixed. The results show that increasing magnon damping suppresses level‐repulsion in the transmission spectra, driving the system from strong coupling regime into the Purcell regime via enhanced spontaneous photon emission into lossy magnons. A quantum theoretical framework accurately captures this behavior and provides estimates of the PMC strength , which can be tuned from 63 to 127 MHz by varying from to . Through simulations and parameter‐space mapping, we demonstrate how damping, photon loss, and coupling strength govern the crossover between coherent coupling and the Purcell regime, while magnon population scaling confirms its cooperative nature. These findings establish a clear route for controlling photon dissipation, enabling on‐chip hybrid devices and quantum technologies based on magnon–photon interactions.