Phonon imaging is employed to examine the propagation of acoustic phonons through a Fibonacci superlattice. Ballistic transmission of phonons with ν>850 GHz through 750 superlattice interfaces is detected. In addition, sharp variations in the phonon intensity with propagation angle are observed. These measurements are consistent with Monte Carlo simulations presented in this paper. Distinct stop bands are expected theoretically, and the angular dependence of these structures is remarkably similar to those predicted for a periodic superlattice.

• Received 16 October 1987

DOI:https://doi.org/10.1103/PhysRevB.37.8829