Sommaire:

The glass transition is the dramatic dynamical slowdown one observes when cooling down a liquid or densifying a set of particles into an amorphous state. During this seminar I will tackle first the relation between the very short term dynamics - essentially made of vibrations of the particles around their equilibrium positions - and the long time scale dynamics where dynamical heterogeneities appear and develop on approach to the glass transition. The dynamics of the metastable states is analyzed in two experimental granular systems (grains under cyclic shear or in a fluidized bed) and in simulations of repulsive particles. I will show that in all these systems, the same dynamical facilitation mechanism is at play. Then, I will turn on the relation between dynamics and structure and raise the issue of predictability by using isoconfigurational ensemble techniques in simulations.

Pour plus d'informations, merci de contacter Stocco A.