Study Of Photon-magnon Coupling In A YIG/split-ring Resonator System

The magnon-polaritons formed by the interaction of photons and magnons has received great attention from many researchers as an important elementary excitation because of its promise to realize quantum memories and quantum transducers in the field of quantum information.The realization of the interaction between photons and magnons in a microwave split-ring resonator not only enables the integration of many quantum characteristics with CMOS platforms,but also gives new research ideas on the interaction between photons and magnons.In this dissertation,starting from the classical coupled harmonic oscillator model,combining Kittel mode,Backward Volume Magnetostatic Waves,Magnetostatic Surface Spin Waves and classical electromagnetic theory,round-sheet single crystal bulk YIG and single crystal thin film YIG are respectively used as research media,using microwave split ring resonators.The interaction between photons and magnons is achieved due to the microwave magnetic field at the SRR center.We also obtain and theoretically explain the standing wave signals of the Backward Volume Magnetostatic Waves and Magnetostatic Surface Spin Waves in the round-sheet sample.We realize the nonuniform microwave magnetic field by changing the width of the ring of the microwave split ring resonator.The variation of the coupling strength under different microwave magnetic fields was obtained in the nonuniform of the microwave magnetic field in the medium.The main innovative results obtained are as follows: 1.Strong coupling of photons and magnons(FMR)in a microwave split ring resonator andround-sheet single crystal bulk YIG system is achieved,with a coupling strength of 65.7 MHz.2.The existence of spin standing wave in round-sheet single crystal bulk YIG needs to be solvedwith the Bessel functions.The coupling images between spin wave magnons and microwavephotons in round-sheet single crystal bulk YIG are obtained.And the coupling images are inagreement with the experimental results.3.By changing relative size between the ring width of the microwave split ring resonator and theof the square thin film YIG sample,the presence or absence of microwave magnetic fields indifferent directions in the sample is changed.And the nonuniform of the microwave magneticfield is used to change the coupling strength.4.Through the controlling of different microwave magnetic field components in the sample andthe direction of the applied magnetic field,the changing of the coupling strength from 52 MHzto 279.45 MHz was realized;and it was found that as the width of the ring decreases,thecoupling strength increases first and then decrease.