Séminaires MSC
"Matière et Systèmes Complexes"

Lundi 9 octobre 2006 à 11h30
Tour 33, couloir 33-43, 2ème étage, salle de réunion

Frédéric Lechenault
(CEA, Saclay)

"Evidence of glassy behavior in granular media: from a macroscopic analogy to a microscopic evidence"

After reviewing experimental results about the behavior of dense granular media under various solicitations close to the so-called jamming transition and the analogy that can be drawn between that kind of system and thermal liquids close to their glass transition, i'll present a new set of experiments designed to precise these similarities down to the microscopic level. I'll show how diffusion and relaxation properties in colloidal glasses and dense granular media are strikingly alike at the level of the particules. Then i'll present a method to characterize the dynamical heterogeneities that appear in these systems and how the associated dynamical length scale depends on the packing fraction.