Low-energy excess of vibrational states in v-SiO2: the role of transverse dynamics

Abstract

The study of the effects of the density variations on the vibrational dynamics in vitreous silica is presented. A detailed analysis of the dynamical structure factor, as well as of the current spectra, allows the identification of a flattened transverse branch which is highly sensitive to the density variations. The experimental variations on the intensity and position of the Boson Peak (BP) in v-SiO2 as a function of density are reproduced and interpreted as being due to the shift and disappearance of the latter band. The BP itself is found to correspond to the lower energy tail of the excess states due to the piling up of vibrational modes at energies corresponding to the flattening of the transverse branch.

arXiv comment6 pages, 5 figures

References in corpus (10)

• Harmonic Vibrational Excitations in Disordered Solids and the "Boson Peak"
• The evolution of vibrational excitations in glassy systems
• High Frequency Dynamics of Amorphous Silica
• The Raman coupling function in amorphous silica and the nature of the long wavelength excitations in disordered systems
• Vibrational spectrum of topologically disordered systems
• High frequency sound waves in vitreous silica
• The nature of the short wavelength excitations in vitreous silica: X-Rays Brillouin scattering study
• Anderson Localization in Euclidean Random Matrices
• q-dependence of low-frequency Raman scattering in silica glass
• Densification effects on the Boson peak in vitreous silica: a molecular-dynamics study

Cited by in corpus (7)

• Modeling the mechanics of amorphous solids at different length and time scales
• Heat transport in model jammed solids
• Boson peak dynamics of glassy glucose studied by integrated terahertz-band spectroscopy
• On the analysis of the vibrational Boson peak and low-energy excitations in glasses
• Role of structural relaxations and vibrational excitations in the high-frequency dynamics of liquids and glasses
• Vibrational behaviour of a realistic amorphous-silicon model
• Universal properties of high-frequency spectra in glass formers