Defect-free localized modes and coupled-resonator acoustic waveguides constructed in two-dimensional phononic quasicrystals

The localization of acoustic waves in defect-free two-dimensional quasiperiodic phononic crystals has been investigated by using an exact multiple-scattering method. Different types of localized states have been found in eightfold, tenfold, and twelvefold two-dimensional phononic quasicrystals without introducing any defect. The defect-free coupled-resonator acoustic waveguides, based on these localized modes, have been designed, and the resonant transmission properties of acoustic waves in the waveguides have been demonstrated by numerical simulations. It is anticipated that our findings can be potentially applied to phononic devices.