Abstract: The point defect and line defect band structure of spoof surface acoustic waves were calculated by the finite element method and the supercell method,and acoustic confinement and waveguiding of surface phononic crystals with defect states were analyzed theoretically.The surface phononic crystal is composed of rigid surface with periodic grooves.Point defects and line defects can be introduced by changing the geometrical parameters of single groove in the core center or one row of grooves.Furthermore,combining the finite element method and the supercell method,it is very convenient to calculate the band structure of point defects and line defects,and obtain the eigen-pressure field of spoof surface acoustic waves which localized in the point defects and the line defects with specific frequency.By analyzing the defect band structure and eigen-pressure field diagram,we can intuitively understand the acoustic confinement and acoustic waveguides in the surface phononic crystal with defect states.

Key words: The point defect and line defect band structure of spoof surface acoustic waves were calculated by the finite element method and the supercell method,and acoustic confinement and waveguiding of surface phononic crystals with defect states were analyzed theoretically.The surface phononic crystal is composed of rigid surface with periodic grooves.Point defects and line defects can be introduced by changing the geometrical parameters of single groove in the core center or one row of grooves.Furthermore,combining the finite element method and the supercell method,it is very convenient to calculate the band structure of point defects and line defects,and obtain the eigen-pressure field of spoof surface acoustic waves which localized in the point defects and the line defects with specific frequency.By analyzing the defect band structure and eigen-pressure field diagram,we can intuitively understand the acoustic confinement and acoustic waveguides in the surface phononic crystal with defect states.