# Impact of elastic heterogeneity on the propagation of vibrations at finite temperatures in glasses

## TL;DR

This study uses molecular dynamics simulations to explore how elastic heterogeneity influences vibrational wave propagation in glasses at finite temperatures, revealing complex transport behaviors.

## Contribution

It provides a detailed analysis of vibrational excitations in glasses, linking elastic heterogeneity to transport properties through simulation and theoretical comparison.

## Key findings

- Elastic heterogeneity significantly affects sound dispersion and attenuation.
- Vibrational transport properties are strongly temperature-dependent.
- Simulation results align with heterogeneous elastic theory predictions.

## Abstract

Some aspects of how sound waves travel through disordered solids are still unclear. Recent work has characterized a feature of disordered solids which seems to influence vibrational excitations at the mesoscales, local elastic heterogeneity. Sound waves propagation has been demonstrated to be strongly affected by inhomogeneous mechanical features of the materials which add to the standard anharmonic couplings, amounting to extremely complex transport properties at finite temperatures. Here, we address these issues for the case of a simple atomic glass former, by Molecular Dynamics computer simulation. In particular, we focus on the transverse components of the vibrational excitations in terms of dynamic structure factors, and characterize the temperature dependence of sound dispersion and attenuation in an extended frequency range. We provide a complete picture of how elastic heterogeneity determines transport of vibrational excitations, also based on a direct comparison of the numerical data with the predictions of the heterogeneous elastic theory.