Enhancement of the microwave photon-magnon coupling strength for a planar fabricated resonator

Abstract

Planar resonators have a wide usage in modern microwave technologies and perspectives in novel quantum technologies development. As was demonstrated earlier, their utilization allows to achieve high values of microwave photon-magnon coupling strength—an important parameter in technologies of information coherent transfer from electromagnetic GHz range to the optical range. In the present work, the achievement of the high value of the microwave photon-magnon coupling strength by exploiting the increase of the spatial concentration of the magnetic component of the planar resonator electromagnetic field is reported. Starting from the conventional planar split-ring resonator design we increased the coupling strength up to 40% by modifying the resonator shape. The numerical simulation and experimental verification showed a predicted increase in the spatial concentration of the microwave magnetic component and showed the increased value of the microwave photon-magnon coupling strength as a sequence.

Controlling magnon-photon coupling in a planar geometry

“…Controlled magnon-photon coupling has previously been demonstrated experimentally in 3D rectangular cavities of different sizes using yttrium iron garnet (YIG) spheres with varying diameters [9,10] and in a 3D cylindrical cavity by varying the angle between the external magnetic field and the microwave field [18]. Similar physics has been demonstrated in planar-geometry resonator-based systems, which exhibit higher coupling strengths than those of the 3D cavity resonator-based systems [19][20][21][22][23], by varying the position of a YIG thin film [24] . Furthermore, it was shown that the coupling can be controlled in a split-ring resonator with a nonuniform microwave magnetic field by changing the track width of the split-ring [25].…”