High Frequency Sound Waves in Vitreous Silica

Abstract

We report a molecular dynamics simulation study of the sound waves in vitreous silica in the mesoscopic exchanged momentum range. The calculated dynamic structure factors are in quantitative agreement with recent experimental inelastic neutron and x-ray scattering data. Analysis of the longitudinal and transverse current spectra allows us to discriminate between opposite interpretations of the existing experimental data in favor of the propagating nature of the high frequency sound waves.