Heterogeneous shear elasticity of glasses: The origin of the boson peak

Alessia Marruzzo, Walter Schirmacher, Andrea Fratalocchi, Giancarlo Ruocco

Research output: Contribution to journalArticlepeer-review

86 Scopus citations

Abstract

The local elasticity of glasses is known to be inhomogeneous on a microscopic scale compared to that of crystalline materials. Their vibrational spectrum strongly deviates from that expected from Debye's elasticity theory: The density of states deviates from Debye's law, the sound velocity shows a negative dispersion in the boson-peak frequency regime and there is a strong increase of the sound attenuation near the boson-peak frequency. By comparing a mean-field theory of shear-elastic heterogeneity with a large-scale simulation of a soft-sphere glass we demonstrate that the observed anomalies in glasses are caused by elastic heterogeneity. By observing that the macroscopic bulk modulus is frequency independent we show that the boson-peak-related vibrational anomalies are predominantly due to the spatially fluctuating microscopic shear stresses. It is demonstrated that the boson-peak arises from the steep increase of the sound attenuation at a frequency which marks the transition from wave-like excitations to disorder-dominated ones.
Original languageEnglish (US)
JournalScientific Reports
Volume3
Issue number1
DOIs
StatePublished - Mar 8 2013

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Heterogeneous shear elasticity of glasses: The origin of the boson peak'. Together they form a unique fingerprint.

Cite this