Ultra-long range correlations of the dynamics of jammed soft matter
Abstract
We use Photon Correlation Imaging, a recently introduced space-resolved dynamic light scattering method, to investigate the spatial correlation of the dynamics of a variety of jammed and glassy soft materials. Strikingly, we find that in deeply jammed soft materials spatial correlations of the dynamics are quite generally ultra-long ranged, extending up to the system size, orders of magnitude larger than any relevant structural length scale, such as the particle size, or the mesh size for colloidal gel systems. This has to be contrasted with the case of molecular, colloidal and granular ``supercooled'' fluids, where spatial correlations of the dynamics extend over a few particles at most. Our findings suggest that ultra long range spatial correlations in the dynamics of a system are directly related to the origin of elasticity. While solid-like systems with entropic elasticity exhibit very moderate correlations, systems with enthalpic elasticity exhibit ultra-long range correlations due to the effective transmission of strains throughout the contact network.
Keywords
Cite
@article{arxiv.1006.5527,
title = {Ultra-long range correlations of the dynamics of jammed soft matter},
author = {Simona Maccarrone and Giovanni Brambilla and Olivier Pravaz and Agnes Duri and Matteo Ciccotti and Jean-Marc Fromental and Eugene Pashkovski and Alex Lips and David A. Sessoms and Veronique Trappe and Luca Cipelletti},
journal= {arXiv preprint arXiv:1006.5527},
year = {2010}
}
Comments
To appear in Soft Matter