Pierre Deltour | Searcharxiv

arXiv1997

Fast diffusion of a Lennard-Jones cluster on a crystalline surface

We present a Molecular Dynamics study of large Lennard-Jones clusters evolving on a crystalline surface. The static and the dynamic properties of the cluster are described. We find that large clusters can diffuse rapidly, as experimentally observed. The role of the mismatch between the lattice parameters of the cluster and the substrate is emphasized to explain the diffusion of the cluster. This diffusion can be described as a Brownian motion induced by the vibrationnal coupling to the substrate, a mechanism that has not been previously considered for cluster diffusion.

cond-mat.mtrl-sci↗

arXiv1996

Quantitative study of a freely cooling granular medium

We present a numerical study of a two dimensional granular medium consisting of hard inelastic disks. The evolution of the medium throughout a cooling process is monitored. Two different types of instabilities (shearing and clustering instability) are found to develop in the system. The development of these instabilities is shown to be in qualitative and quantitative agreement with the predictions of linearized hydrodynamic theory.

cond-mat↗