2 research outputs found
Avalanches and Dynamical Correlations in supercooled liquids
We identify the pattern of microscopic dynamical relaxation for a two
dimensional glass forming liquid. On short timescales, bursts of irreversible
particle motion, called cage jumps, aggregate into clusters. On larger time
scales, clusters aggregate both spatially and temporally into avalanches. This
propagation of mobility, or dynamic facilitation, takes place along the soft
regions of the systems, which have been identified by computing
isoconfigurational Debye-Waller maps. Our results characterize the way in which
dynamical heterogeneity evolves in moderately supercooled liquids and reveal
that it is astonishingly similar to the one found for dense glassy granular
media.Comment: 4 pages, 3 figure
Critical fluctuations and breakdown of Stokes-Einstein relation in the Mode-Coupling Theory of glasses
We argue that the critical dynamical fluctuations predicted by the
mode-coupling theory (MCT) of glasses provide a natural mechanism to explain
the breakdown of the Stokes-Einstein relation. This breakdown, observed
numerically and experimentally in a region where MCT should hold, is one of the
major difficulty of the theory, for which we propose a natural resolution based
on the recent interpretation of the MCT transition as a bona fide critical
point with a diverging length scale. We also show that the upper critical
dimension of MCT is d_c=8.Comment: Proceedings of the workshop on non-equilibrium phenomena in
supercooled fluids, glasses and amorphous materials (17-22 September, 2006,
Pisa