Crystallization of a quasi-two-dimensional granular fluid

TL;DR

This study experimentally explores how a heated quasi-2D granular fluid crystallizes, finding that its behavior aligns with equilibrium hard disk simulations, indicating equilibrium concepts can apply to non-equilibrium systems.

Contribution

It demonstrates that non-equilibrium granular systems exhibit equilibrium-like crystallization behavior, validated through multiple structural and statistical measures.

Findings

Lindemann melting criterion matches equilibrium predictions

Radial distribution functions are similar to equilibrium systems

Topological change statistics align with equilibrium hard disk results

Abstract

We experimentally investigate the crystallization of a uniformly heated quasi-2D granular fluid as a function of filling fraction. Our experimental results for the Lindemann melting criterion, the radial distribution function, the bond order parameter and the statistics of topological changes at the particle level are the same as those found in simulations of equilibrium hard disks. This direct mapping suggests that the study of equilibrium systems can be effectively applied to study non-equilibrium steady states like those found in our driven and dissipative granular system.