Vibrational states and disorder in continuously compressed model glasses

Poisson ratio and excess low-frequency vibrational states in glasses.

In glass, starting from a dependence of the Angell's fragility on the Poisson ratio [V. N. Novikov and A. P. Sokolov, Nature 431, 961 (2004)], and a dependence of the Poisson ratio on the atomic packing density [G. N. Greaves, A. L. Greer, R. S. Lakes, and T. Rouxel, Nature Mater. 10, 823 (2011)], we propose that the heterogeneities are predominantly density fluctuations in strong glasses (lowe...

Vibrational Modes of Glasses - Effects of Disorder and Nonlinearity

Vibrational spectra in glasses

The findings of X-ray and neutron scattering experiments on amorphous systems are interpreted within the framework of the theory of Euclidean random matrices. This allows to take into account the topological nature of the disorder, a key ingredient which strongly affects the vibrational spectra of those systems. We present a resummation scheme for a perturbative expansion in the inverse particl...

Excess Vibrational Modes and the Boson Peak in Model Glasses

The excess low-frequency normal modes for two widely used models of glasses are studied at zero temperature. The onset frequencies for the anomalous modes for both systems agree well with predictions of a variational argument, which is based on analyzing the vibrational energy originating from the excess contacts per particle over the minimum number needed for mechanical stability. Even though ...

Vibrational modes of partly filled wine glasses

Time-average holographic interferometry has been employed to study how the vibrational modes of a singing wine glass change when it is filled with a liquid. While the liquid clearly lowers the resonance frequencies, it does not change the vibrational mode structure in a first approximation. A more detailed analysis, however, reveals that the presence of the liquid causes the simultaneous excita...