Comment on 'Repulsive Contact Interactions Make Jammed Particulate Systems Inherently Nonharmonic'

TL;DR

This paper challenges prior claims that large jammed particulate systems lack a harmonic regime, arguing instead that linear response remains valid and crucial for understanding jammed solids.

Contribution

The authors dispute previous conclusions by demonstrating that linear response theory is justified and essential in jammed particulate systems, countering claims of inherent nonharmonicity.

Findings

Linear response remains valid in jammed systems.

Breaking a contact does not necessarily destroy harmonic behavior.

Linear response is crucial for understanding jammed solids.

Abstract

In their Letter, Schreck, Bertrand, O'Hern and Shattuck [Phys. Rev. Lett. 107, 078301 (2011)] study nonlinearities in jammed particulate systems that arise when contacts are altered. They conclude that there is "no harmonic regime in the large system limit for all compressions" and "at jamming onset for any system size." Their argument rests on the claim that for finite-range repulsive potentials, of the form used in studies of jamming, the breaking or forming of a single contact is sufficient to destroy the linear regime. We dispute these conclusions and argue that linear response is both justified and essential for understanding the nature of the jammed solid.