Using simulations of hard rods in smectic-A states, we find non-gaussian diffusion and heterogeneous dynamics due to the equilibrium periodic smectic density profiles, which give rise to permanent barriers for layer-to-layer diffusion. This relaxation behavior is surprisingly similar to that of non-equilibrium supercooled liquids, although there the particles are trapped in transient (instead of permanent) cages. Interestingly, we also find stringlike clusters of up to 10 inter-layer rods exhibiting dynamic cooperativity in this equilibrium state.
@article{arxiv.0906.3093,
title = {Dynamical Heterogeneities and Cooperative Motion in Smectic Liquid Crystals},
author = {A. Patti and D. El Masri and R. van Roij and M. Dijkstra},
journal= {arXiv preprint arXiv:0906.3093},
year = {2009}
}