Weak disorder: anomalous transport and diffusion are normal yet again

TL;DR

This paper explores how adding spatial disorder to a periodic potential influences particle transport, revealing complex behaviors like superdiffusion, subdiffusion, and subtransport beyond simple diffusion enhancement.

Contribution

It uncovers a rich phenomenology of transport behaviors induced by disorder, extending understanding of particle dynamics in disordered periodic systems.

Findings

Disorder can induce superdiffusion and subdiffusion.

Transport behaviors vary significantly with system parameters.

Disorder effects are more complex than previously understood.

Abstract

Particles driven through a periodic potential by an external constant force are known to exhibit a pronounced peak of the diffusion around a critical force that defines the transition between locked and running states. It has recently been shown both experimentally and numerically that this peak is greatly enhanced if some amount of spatial disorder is superimposed on the periodic potential. Here we show that beyond a simple enhancement lies a much more interesting phenomenology. For some parameter regimes the system exhibits a rich variety of behaviors from normal diffusion to superdiffusion, subdiffusion and even subtransport.