Low-frequency vibrations of jammed packings in large spatial dimensions

TL;DR

This study investigates the vibrational properties of large amorphous packings near the jamming transition across dimensions 3 to 9, finding that non-Debye scaling persists at lower frequencies as dimension increases, aligning with mean-field predictions.

Contribution

It provides extensive numerical evidence on the validity of non-Debye scaling in high-dimensional jammed packings, extending previous studies to larger system sizes and higher dimensions.

Findings

Non-Debye scaling persists down to lower frequencies as dimension increases.

The frequency range of non-Debye scaling shrinks with increasing dimension.

Mean-field predictions are supported for large dimensions.

Abstract

Amorphous packings prepared in the vicinity of the jamming transition play a central role in theoretical studies of the vibrational spectrum of glasses. Two mean-field theories predict that the vibrational density of states $g(\omega)$ obeys a characteristic power law, $g(\omega)\sim\omega^2$, called the non-Debye scaling in the low-frequency region. Numerical studies have however reported that this scaling breaks down at low frequencies, due to finite dimensional effects. In this study, we prepare amorphous packings of up to $128000$ particles in spatial dimensions from $d=3$ to $d=9$ to characterise the range of validity of the non-Debye scaling. Our numerical results suggest that the non-Debye scaling is obeyed down to a frequency that gradually decreases as $d$ increases, and possibly vanishes for large $d$, in agreement with mean-field predictions. We also show that the prestress is an efficient control parameter to quantitatively compare packings across different spatial dimensions.