Research On Magnon Coupling And Dynamic Regulation Of Magnetic Insulator Film

Conventional electronic devices are based on nonmagnetic semiconductors and use the controlled flow of electric charges to achieve information processing and communication.However,with the gradual development of information devices towards miniaturization and integration,the problems of quantum effect and power consumption are becoming more and more serious,resulting in the slow down of device scaling based on Moore's Law and its associated performance scaling trend.In order to overcome the problems caused by traditional CMOS technology,information processing technology using electron spin has been widely concerned.Compared to conventional microelectronic devices based on charge,spintronic devices require less energy to switch a spin state,which can result in faster operation speed and lower energy consumption.Therefore,spintronics is the most promising technology to develop alternative multifunctional,high-speed,low-energy electronic devices.According to the above,the ferrimagnetic insulator film heterostructure samples were prepared by pulsed laser deposition system in thesis,and the dynamic magnon coupling effect in the ferrimagnetic film heterostructure samples was studied by ferromagnetic resonance and spin wave detection.Then,an on-chip integrated magnetostatic wave resonator was designed and fabricated based on the ferrimagnetic insulator YIG single-crystal film.Firstly,dynamic magnon coupling was investigated in ferrimagnetic-ferrimagnetic(YIG/Tm Bi IG)and ferrimagnetic-nonmagnetic-ferrimagnetic(YIG/GGG/Tm Bi IG)film heterostructures using broadband ferromagnetic resonance.The magnon spin pumping effect was observed experimentally in the YIG/Tm Bi IG film heterostructures.Hybrid magnon coupling modes were found in the YIG/Tm Bi IG and YIG/GGG/Tm Bi IG systems.Tremendous Gilbert damping enhancement was observed in the YIG/Tm Bi IG system,indicating a strong magnon spin current pumped under resonance conditions in the coupled magnon system.The magnon spin current conductance is strongly dependent on the interlayer exchange coupling strength.In contrast,the mutual pumping magnon current between YIG and Tm Bi IG was blocked significantly by the nonmagnetic GGG spacer layer.However,a phonon spin current in the nonmagnetic GGG layer coupled the magnon spin currents in the YIG and Tm Bi IG layers indirectly,preserving the coherent magnon-magnon coupling.Remarkably,magnonic Fano line shapes were found for the optical hybrid modes in the YIG/Tm Bi IG and YIG/GGG/Tm Bi IG film heterostructures and were attributed to interference of the resonance mode and the pumped phonon spin current.The dynamic magnon-phonon coupling between YIG and GGG substrates was revealed in the spin wave test.Secondly,an on-chip integrated magnetostatic wave resonator was designed using HFSS software,and the resonator was fabricated by patterning a YIG single-crystal film on a GGG substrate and exciting the magnetostatic wave by a short-circuited coplanar waveguide.The miniaturization of the device is achieved through microfabrication processes such as photoetching and etching.By adjusting the center frequency of the resonator by changing the bias magnetic field,the maximum Q-factor can reach 3128,showing good performance.