Experimental study of the jamming transition at zero temperature

TL;DR

This study experimentally explores the structural and dynamic signatures of the jamming transition at zero temperature in a granular system, revealing key correlation peaks, cluster growth, and the effects of friction.

Contribution

It identifies the pair correlation function peaks as structural signatures of jamming and demonstrates how friction induces stepwise jamming through force chain buckling.

Findings

Peak in the first and second pair correlation functions signals jamming.

Cluster size approaches system size near jamming point.

Friction causes jamming in steps via buckling of force chains.

Abstract

We experimentally investigate jamming in a quasi-two-dimensional granular system of automatically swelling particles and show that a maximum in the height of the first peak of the pair correlation function is a structural signature of the jamming transition at zero temperature. The same signature is also found in the second peak of the pair correlation function, but not in the third peak, reflecting the underlying singularity of jamming transition. We also study the development of clusters in this system. A static length scale extracted from the cluster structure reaches the size of the system when the system approaches the jamming point. Finally, we show that in a highly inhomogeneous system, friction causes the system to jam in series of steps. In this case, jamming may be obtained through successive buckling of force chains.