Glassy Dislocation Dynamics in 2-D Colloidal Dimer Crystals
Abstract
Although glassy relaxation is typically associated with disorder, here we report on a new type of glassy dynamics relating to dislocations within 2-D crystals of colloidal dimers. Previous studies have demonstrated that dislocation motion in dimer crystals is restricted by certain particle orientations. Here, we drag an optically trapped particle through such dimer crystals, creating dislocations. We find a two-stage relaxation response where initially dislocations glide until encountering particles that cage their motion. Subsequent relaxation occurs logarithmically slowly through a second process where dislocations hop between caged configurations. Finally, in simulations of sheared dimer crystals, the dislocation mean squared displacement displays a caging plateau typical of glassy dynamics. Together, these results reveal a novel glassy system within a colloidal crystal.
Cite
@article{arxiv.1008.1919,
title = {Glassy Dislocation Dynamics in 2-D Colloidal Dimer Crystals},
author = {Sharon J. Gerbode and Umang Agarwal and Desmond C. Ong and Chekesha M. Liddell and Fernando Escobedo and Itai Cohen},
journal= {arXiv preprint arXiv:1008.1919},
year = {2010}
}
Comments
4 pages + 2 page supp. mat