Nonlinear Split-Ring Resonator for Controlling the Strong Photon-Magnon Coupling Strength

Abstract

The strong coupling effect between magnons and photons in a nonlinear split-ring shaped resonator was studied numerically. It has been shown that in the nonlinear regime, a structure with a variable capacitor Cv=0.1 pF exhibits a maximum value of the strength of strong coupling between photons and magnons $(\mathrm{g} / 2 \pi=52 \text{MHz})$ with a strength of coupling normalized per spin (coupling of a single-spin photon) of $g/2\pi\sqrt{N}= 0.1605 \text{Hz}$ at a frequency of 1.163 GHz. The possibility of tuning the frequency of resonance of the studied resonant structure by varying the degree of nonlinearity of the electrodynamic processes occurring within it has been demonstrated. Namely, we have shown that in the nonlinear regime, the control of the frequency of resonance of the structure and the magnitude of photon-magnon coupling by varying the input power Pin is possible. Additionally, an increase in photon-magnon coupling with decreasing variable capacitor capacitance was observed. © 2025 Elsevier B.V., All rights reserved.