We have investigated co-directional and contra-directional couplings betweenspin wave and acoustic wave in one-dimensional periodic structure (magphoniccrystal). The system consists of two ferromagnetic layers alternating in space.We have taken into consideration materials commonly used in magnonics: yttriumiron garnet, CoFeB, permalloy, and cobalt. The coupled mode theory (CMT)formalism have been successfully implemented to describe magnetoelasticinteraction as a periodic perturbation in the magphonic crystal. The results ofCMT calculations have been verified by more rigorous simulations byfrequency-domain plane wave method and time-domain finite element method. Thepresented resonant coupling in the magphonic crystal is an active in-spacemechanism which spatially transfers energy between propagating spin andacoustic modes, thus creating propagating magnetoelastic wave. We have shown,that CMT analysis of the magnetoelastic coupling is an useful tool to optimizeand design a spin wave - acoustic wave transducer based on a magphoniccrystals. The effect of spin wave damping has been included to the model todiscuss the efficiency of such a device. Our model shows that it is possible toobtain forward conversion of the acoustic wave to the spin wave in case ofco-directional coupling and backward conversion in case of contra-directionalcoupling.
展开▼
