Diffusion and transport in locally disordered driven lattices

TL;DR

This paper investigates how localized disorder in a driven lattice affects particle density evolution and transport, revealing non-Gaussian distributions and enhanced transport due to phase space conversions.

Contribution

It introduces a theoretical model linking phase space conversions to density scaling, highlighting the distinct effects of localized versus global disorder on transport.

Findings

Localized disorder causes non-Gaussian density tails.

Disorder-induced phase space conversions enhance transport.

Global disorder has a weaker impact on transport.

Abstract

We study the effect of disorder on the particle density evolution in a classical Hamiltonian driven lattice setup. If the disorder is localized within a finite sub-domain of the lattice, the emergence of strong tails in the density distribution which even increases towards larger positions is shown, thus yielding a highly non Gaussian particle density evolution. As the key underlying mechanism we identify the conversion between different components of the unperturbed systems mixed phase space which is induced by the disorder. Based on the introduction of individual conversion rates between chaotic and regular components, a theoretical model is developed which correctly predicts the scaling of the particle density. The effect of disorder on the transport properties is studied where a significant enhancement of the transport for cases of localized disorder is shown, thereby contrasting strongly the merely weak modification of transport for global disorder.