2003/12/02 by S. Ciliberti, T. S. Grigera, V. Martin-Mayor +2 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Material Dynamics and Properties #Metallic Glasses and Amorphous Alloys #Phase-change materials and chalcogenides #cond-mat
paper · pdf · doi:10.1063/1.1764225
to appear in the proceedings of the conference "Slow dynamics in complex sistems", Sendai (Japan) 2003
arxiv created 2003/12/02 · openalex publication_date 2004/01/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Despite the presence of topological disorder, phonons seem to exist also in glasses at very high frequencies (THz) and they remarkably persist into the supercooled liquid. A universal feature of such a systems is the Boson peak, an excess of states over the standard Debye contribution at the vibrational density of states. Exploiting the euclidean random matrix theory of vibrations in amorphous systems, we show that this peak is the signature of a phase transition in the space of the stationary points of the energy, from a minima‐dominated phase (with phonons) at low energy to a saddle‐point dominated phase (without phonons). The theoretical predictions are checked by means of numeric simulations.