Enhancement of Magnon–Photon Coupling Strength: Effect of Spatial Distribution

Abstract

Magnon–photon hybrid systems have potential applications in quantum information processing. The spatial distribution of magnetic field intensity plays a crucial role in enhancing coupling strength. We have investigated strong magnon–photon coupling using a planar waveguide with defects in the ground for dual-frequency ranging from S to C band. Dual inverted split ring resonators were used as a photon resonator, and a yttrium iron garnet (YIG) pellet acted as a magnon source. The interaction between magnon and photon modes was manipulated by variations in the spatial distribution of the magnetic field along the microstrip line. The ferrite sample was placed at three different positions, viz., A, B, and C. The coupling strength $g$ was tuned from 188 to 281 MHz by varying YIG locations at different positions along the microstrip line. The spin-number-normalized coupling strength was significantly tuned up to 50% by controlling the position of YIG. Hence, it provides another degree of freedom for the qubit information exchange. The other parameters such as cooperativity and coupling constant were also determined. This work paves the way for developing innovative hybrid systems with tunable high-gain magnon–photon coupling systems in planar geometry.