Surface Phonon Scattering by Density Fluctuation on Solid Surfaces

Abstract

Since the real surface of solids is rather rough, surface phonons are scattered considerably by the surface irregularities. The present authors calculated the frequency and correlation length dependence of the damping rate of surface phonons due to the density fluctuations on solid surfaces in a previous work[1], hereafter referred to I. It is assumed there that the density fluctuation is localized on solid surfaces. In this report we extend I to allow the density fluctuations with finite depth from solid surfaces. The frequency and correlation length dependence of the rate is calculated on the basis of Gaussian distributed density-fluctuation.