The Raman coupling function in amorphous silica and the nature of the long wavelength excitations in disordered systems

Abstract

New Raman and incoherent neutron scattering data at various temperatures and molecular dynamic simulations in amorphous silica, are compared to obtain the Raman coupling coefficient $C(\omega )$ and, in particular, its low frequency limit. This study indicates that in the $\omega \to 0$ limit $C(\omega )$ extrapolates to a non vanishing value, giving important indications on the characteristics of the vibrational modes in disordered materials; in particular our results indicate that even in the limit of very long wavelength the local disorder implies non-regular local atomic displacements.

Revtex, 4 ps figures

References in corpus (3)

• High frequency sound waves in vitreous silica
• Raman scattering from fractals. Simulation on large structures by the method of moments
• Low-frequency Raman scattering in model disordered solids: percolators above threshold

Cited by in corpus (11)

• Frequency behavior of Raman coupling coefficient in glasses
• Low-energy excess of vibrational states in v-SiO2: the role of transverse dynamics
• Fast Dynamics in a Model Metallic Glass-forming Material
• Scaling the Temperature-dependent Boson Peak of Vitreous Silica with the high-frequency Bulk Modulus derived from Brillouin Scattering Data
• Pressure dependence of the Boson peak in glassy As2S3 studied by Raman Scattering
• The Raman coupling function in disordered solids: a light and neutron scattering study on glasses of different fragility
• The crossover from propagating to strongly scattered acoustic modes of glasses observed in densified silica
• Densification effects on the Boson peak in vitreous silica: a molecular-dynamics study
• Dynamic Kerr effect responses in the Terahertz-range
• Nonresonant holeburning in the Terahertz range: Brownian oscillator model
• Microstructure and the Boson-peak in thermally-treated In_{x}O films