The Inherent Structure Landscape Connection Between Liquids, Granular materials and the Jamming Phase Diagram

TL;DR

This paper explores the connection between liquids, granular materials, and the jamming phase diagram by analyzing inherent structures in a confined hard disc system, revealing the nature of jammed states and the J-point.

Contribution

It introduces a unified framework linking granular and fluid states through the inherent structure paradigm, clarifying the nature of the J-line and J-point in the phase diagram.

Findings

J-line divided into accessible and inaccessible packings

J-point occurs at the transition between these packings

Granular and fluid systems share inherent structures only at zero and infinite pressures

Abstract

We provide a comprehensive picture of the jamming phase diagram by connecting the athermal, granular ensemble of jammed states and the equilibrium fluid through the inherent structure paradigm for a system hard discs confined to a narrow channel. The J-line is shown to be divided into packings that are thermodynamically accessible from the equilibrium fluid and inaccessible packings. The J-point is found to occur at the transition between these two sets of packings and is located at the maximum the inherent structure distribution. A general thermodynamic argument suggests that the density of the states at the configurational entropy maximum represents a lower bound on the J-point density in hard sphere systems. Finally, we find that the granular and fluid systems only occupy the same set of inherent structures, under the same thermodynamic conditions, at two points, corresponding to zero and infinite pressures, where they sample the J-point states and the most dense packing respectively.