Acoustic-phonon transmission in quasiperiodic superlattices

Abstract

Acoustic-phonon transmission through a realistic Fibonacci superlattice is studied theoretically. We find a number of transmission dips corresponding to Bragg-like reflections of phonons. The transmission spectrum is much more complex than in the periodic case; however, the strongest dips in transmission are remarkably correlated with those of the periodic superlattice. We also present the first realistic calculations of the phonon dispersion relations in an actual quasiperiodic superlattice. For oblique angles of incidence, intermode Bragg-like reflections of the phonons are predicted.