Athermal Jamming vs. glassy dynamics for particles with exponentially decaying repulsive pair interaction potentials with a cutoff

TL;DR

This paper investigates the differences between athermal jamming and thermal glassy dynamics in particle systems with exponentially decaying interactions, highlighting the unphysical dependence of jamming on simulation cutoffs and emphasizing the need for more realistic models.

Contribution

It demonstrates that athermal jamming depends on arbitrary cutoffs and is unrelated to thermal glassy dynamics, advocating for models without sharp cutoffs to better understand jamming phenomena.

Findings

Athermal jamming depends on the cutoff choice.

No universal athermal jamming transition based solely on decay length.

Glassy dynamics mainly depends on the decay length.

Abstract

We study athermal jamming as well as the thermal glassy dynamics in systems composed of spheres that interact according to repulsive interactions that exponentially decay as a function of distance. As usual, a cutoff is employed in the simulations. While the athermal jamming transition that is determined by trying to remove overlaps is found to depend on the arbitrary and therefore unphysical choice of the cutoff, we do not find any athermal jamming transition or crossover that only relies on the physical decay length. In contrast, the glassy dynamics mainly depends on the decay length. Our findings constitute another demonstration of the fact that the athermal jamming transition is not related to thermal glassy dynamics. In addition, we argue that interactions without sharp physical cutoff should be considered more often as a model system in jamming. By exploring how widely-used theoretical approaches or methods of analysis in the field of jamming have to be changed in order to not depend on unphysical cutoffs will lead to deeper insights into the nature of athermal and thermal jamming.