Dynamical instability in driven colloids
S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III Salt Lake, Calcutta, 700091, India
2 Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf Universitätsstraße 1, D-40225 Düsseldorf, Germany
Accepted: 25 November 2002
Brownian-dynamics computer simulations show a dynamical crossover in a strongly interacting colloidal suspension consisting of oppositely driven particles, wherein a uniform state transforms, with increasing driving force, into a locally demixed state characterized by strongly anisotropic stripe-like domains which are homogeneous in the direction parallel to the drive but have finite spatial extent of a double-correlation length in the transverse direction. A phenomenological dynamic density-functional theory has been proposed which accounts for such a strongly anisotropic state as arising from an instability of a homogeneous state.
PACS: 82.70.-y – Disperse systems; complex fluids / 61.20.-p – Structure of liquids / 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion
© EDP Sciences, 2003