We study the propagation of a surface acoustic wave of shear horizontal polarization in a system that consists of a thin film of one elastic medium bonded to a semi-infinite substrate of a second elastic medium. The mass density of the medium constituting the thin film is assumed to be a random function of the coordinate defining the direction of propagation of the surface acoustic wave. From an examination of a two-surface-wave Green’s function, averaged over the ensemble of realizations of the mass density in the film, we find that the shear horizontal surface acoustic wave is localized along its direction of propagation by the random fluctuations of this mass density, and its localization length is determined.

• Received 12 September 1988

DOI:https://doi.org/10.1103/PhysRevB.39.2125