Anomalous Dynamical Responses in a Driven System

TL;DR

This study investigates how structural correlations influence anomalous diffusion behaviors in a driven colloidal system, revealing the microscopic basis of heterogeneity in non-equilibrium steady states.

Contribution

It demonstrates the role of structural correlation length in controlling heterogeneity and anomalous dynamics in a driven binary colloid system, providing a generalized theoretical framework.

Findings

Structural correlations determine diffusion heterogeneity.

Anomalous responses include exponential tails and stretched exponential relaxation.

Theoretical equations help understand microscopic diffusion mechanisms.

Abstract

The interplay between structure and dynamics in non-equilibrium steady-state is far from understood. We address this interplay by tracking Brownian Dynamics trajectories of particles in a binary colloid of opposite charges in an external electric field, undergoing cross-over 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 probability distributions of particle displacements and stretched exponential structural relaxation. We generalise our observations using equations for steady state density which may aid to understand microscopic basis of heterogeneous diffusion in condensed matter systems.