Subdiffusion and cage effect in a sheared granular material

TL;DR

This study experimentally explores subdiffusion and cage effects in sheared granular materials, revealing strong analogies with glassy systems and providing detailed insights into slow relaxation dynamics.

Contribution

It presents the first detailed experimental analysis of cage dynamics and subdiffusion in sheared granular matter, linking it to glass transition phenomena.

Findings

Granular materials exhibit cage effects similar to glassy systems.

Subdiffusive behavior is observed during slow relaxation.

Time and length scales of cage dynamics are quantified.

Abstract

We investigate experimentally the diffusion properties of a bidimensional bidisperse dry granular material under quasistatic cyclic shear.The comparison of these properties with results obtained both in computer simulations of hard spheres systems and Lenard-Jones liquids and experiments on colloidal systems near the glass transition demonstrates a strong analogy between the behaviour of granular matter and these systems. More specifically, we study in detail the cage dynamics responsible for the subdiffusion in the slow relaxation regime, and obtain the values of relevant time and length scales.