Superdiffusive, heterogeneous, and collective particle motion near the fluid-solid transition in athermal disordered materials

¹  Université de Lyon; Univ. Lyon I, Laboratoire de Physique de la Matière Condensée et Nanostructures; UMR CNRS 5586 - 69622 Villeurbanne, France, EU
²  Laboratoire des Colloïdes, Verres et Nanomatériaux, UMR CNRS 5587, Université Montpellier 2 34095 Montpellier, France, EU

Corresponding author: claus.heussinger@univ-lyon1.fr

Received: 26 January 2010
Accepted: 13 April 2010

Abstract

We use computer simulations to study the microscopic dynamics of an athermal assembly of soft particles near the fluid-to-solid jamming transition. Borrowing tools developed to study dynamic heterogeneity near glass transitions, we discover a number of original signatures of the jamming transition at the particle scale. We observe superdiffusive, spatially heterogeneous, and collective particle motion over a characteristic scale which displays a surprising non-monotonic behavior across the transition. In the solid phase, the dynamics is an intermittent succession of elastic deformations and plastic relaxations, which are both characterized by scale-free spatial correlations and system size dependent dynamic susceptibilities. Our results show that dynamic heterogeneities in dense athermal systems and glass formers are very different, and shed light on recent experimental reports of “anomalous” dynamical behavior near the jamming transition of granular and colloidal assemblies.