Neutron scattering evidence on the nature of the boson peak

dc.creatorBuchenau, U.
dc.creatorWischnewski, A.
dc.creatorOhl, M.
dc.creatorFabiani, E.
dc.date2004-07-06
dc.date.accessioned2026-07-07T02:59:02Z
dc.date.available2026-07-07T02:59:02Z
dc.descriptionA close inspection of neutron spectra of glass formers in the frequency region above the boson peak does not show the constant eigenvalue density expected for a random dynamical matrix, but a slow decrease towards higher eigenvalues. In 1,4-polybutadiene and selenium, the slope becomes steeper with increasing temperature in the undercooled liquid, suggesting an influence of the vibrational entropy. One can describe the behaviour quantitatively in terms of a balance between level repulsion (from the randomness of the dynamical matrix) and vibrational entropy. On the basis of this evidence, the boson peak must be a crossover from such a balance at higher frequencies to a mixture of sound waves and additional excitations at low frequency.
dc.descriptionLetter, 4 pages, 4 figures, 24 references
dc.identifierhttps://arxiv.org/abs/cond-mat/0407136
dc.identifierhttp://arxiv.org/abs/cond-mat/0407136
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/24355
dc.subjectDisordered Systems and Neural Networks
dc.titleNeutron scattering evidence on the nature of the boson peak
dc.typetext

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