Anomalous dynamical responses in a driven system

¹ Department of Chemical Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences Block-JD, Sector-III, Salt Lake, Kolkata 700098, India
² The Thematic Unit of Excellence on Computational Materials Science, S. N. Bose National Centre for Basic Sciences Block-JD, Sector-III, Salt Lake, Kolkata 700098, India

Received: 11 August 2016
Accepted: 17 November 2016

Abstract

The interplay between structure and dynamics in non-equilibrium steady-state is far from understood. We address this issue by tracking Brownian Dynamics trajectories of particles in a binary colloid of opposite charges in an external electric field. The particles show crossover from homogeneous to lane state, a prototype of heterogeneous structure formation in non-equilibrium systems. We show that the length scale of structural correlations controls heterogeneity in diffusion and consequent anomalous dynamic responses, like the exponential tail in the probability distributions of particle displacements and stretched exponential structural relaxation. We generalise our observations using equations for steady-state density which may help to understand the microscopic basis of heterogeneous diffusion in condensed matter systems.