Spatially heterogeneous dynamics in granular compaction

TL;DR

This paper demonstrates that slowly compacting granular media exhibit spatially correlated dynamic structures similar to those in glass-forming liquids, indicating dynamic heterogeneity as a common feature in jamming materials.

Contribution

It analytically and numerically shows the emergence of spatially correlated dynamics in dense granular media, linking it to phenomena observed in other jammed systems.

Findings

Logarithmically slow dynamics at large times.

Presence of spatially extended dynamic heterogeneity.

Similarity of granular dynamics to glass-forming liquids.

Abstract

We prove the emergence of spatially correlated dynamics in slowly compacting dense granular media by analyzing analytically and numerically multi-point correlation functions in a simple particle model characterized by slow non-equilibrium dynamics. We show that the logarithmically slow dynamics at large times is accompanied by spatially extended dynamic structures that resemble the ones observed in glass-forming liquids and dense colloidal suspensions. This suggests that dynamic heterogeneity is another key common feature present in very different jamming materials.