The transit time of sound in a phononic crystal

Electron material waves cannot permeate a periodic atomic lattice at each energy or frequency. There exists forbidden gap due to the periodicity of atoms. In analogy, acoustic penetrate phononic sonic crystal A two-dimensional consists cylinders. The is adjusted according wavelength sound. Depending on frequency, there exist “allowed” bands with propagation as well “forbidden” band without corresponding bandgap in semiconductor. mathematical description phenomena and technically similar. Here, we investigate experimentally velocity sound by measurement wave’s transit time through crystal. depends frequency smaller than air.