Phononic crystals of spherical particles: A tight binding approach

摘要: The vibrational dynamics of a fcc phononic crystal spheres is studied and compared with that single free sphere, modelled either by continuous homogeneous medium or finite cluster atoms. For weak interaction among the spheres, described shallow bands, low degree dispersion, corresponding to acoustic spheroidal torsional modes sphere. phonon displacements are therefore related vibrations as electron wave functions in atomic tight binding model. Important dispersion found for two lowest which correspond zero frequency translation rotation Brillouin scattering spectra calculated at some values exchanged wavevectors light, those With between particles, given high impedance mismatch dry systems, density states consist sharp bands separated large gaps, can be well accounted particle Based on width tunable size, small number dispersive phonons, such systems may provide excellent materials application sound heat filters.