New jamming scenario: From marginal jamming to deep jamming

TL;DR

This paper investigates the transition from marginal to deep jamming in frictionless sphere packings, revealing structural and vibrational differences that define a new class of amorphous solids.

Contribution

It identifies a crossover volume fraction and characterizes the distinct properties of deeply jammed solids compared to marginally jammed ones.

Findings

Different scaling laws in deeply jammed solids

Structural changes in pair distribution functions

Anomalies in vibrational modes and density of states

Abstract

We study properties of jammed packings of frictionless spheres over a wide range of volume fractions. There exists a crossover volume fraction which separates deeply jammed solids from marginally jammed solids. In deeply jammed solids, all the scalings presented in marginally jammed solids are replaced with remarkably different ones with potential independent exponents. Correspondingly, there are structural changes in the pair distribution function associated with the crossover. The normal modes of vibration of deeply jammed solids also exhibit some anomalies, e.g. strengthened quasi-localization and absence of Debye-like density of states at low frequencies. Deeply jammed systems may thus be cataloged to a new class of amorphous solids.