Dynamical structure factor in disordered systems
We study the spectral width as a function of the external momentum for the dynamical structure factor of a disordered harmonic solid, considered as a toy model for supercooled liquids and glasses. In the contexts of both the single-link coherent potential approximation and a single-defect approximat...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2000 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/60329 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/60329 |
| Access Level: | acceso abierto |
| Palabra clave: | 53 Frequency propagating modes Instantaneous normal-modes Spectral moments method Vitreous silica Medium approximation LIquids Scattering Glass Localization Phonons. Física-Modelos matemáticos |
| Sumario: | We study the spectral width as a function of the external momentum for the dynamical structure factor of a disordered harmonic solid, considered as a toy model for supercooled liquids and glasses. In the contexts of both the single-link coherent potential approximation and a single-defect approximation, two different regimes are clearly identified: if the density of states at zero energy is zero, the usual p^(4) law is recovered for small momentum. On the contrary, if the disorder induces a nonvanishing density of states at zero energy, a linear behavior is obtained. The dynamical structure factor is numerically calculated in lattices as large as 96^(3) and satisfactorily agrees with the analytical computations. |
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