Strong Mobility in Weakly Disordered Systems

TL;DR

This paper investigates how weak disorder in one-dimensional systems with interacting particles can significantly enhance particle mobility, leading to super-diffusive behavior, contrary to the sub-diffusive case without disorder.

Contribution

The study reveals that weak disorder causes super-diffusive transport in interacting particle systems, supported by scaling arguments and numerical simulations, highlighting a counterintuitive mobility enhancement.

Findings

Disorder induces super-diffusive growth of displacement, sigma ~ (epsilon t)^{2/3}.

Without disorder, displacement is sub-diffusive, sigma ~ t^{1/4}.

Disorder generally increases particle mobility.

Abstract

We study transport of interacting particles in weakly disordered media. Our one-dimensional system includes (i) disorder: the hopping rate governing the movement of a particle between two neighboring lattice sites is inhomogeneous, and (ii) hard core interaction: the maximum occupancy at each site is one particle. We find that over a substantial regime, the root-mean-square displacement of a particle, sigma, grows super-diffusively with time t, sigma ~ (epsilon t)^{2/3}, where epsilon is the disorder strength. Without disorder the particle displacement is sub-diffusive, sigma ~ t^{1/4}, and therefore disorder dramatically enhances particle mobility. We explain this effect using scaling arguments, and verify the theoretical predictions through numerical simulations. Also, the simulations show that disorder generally leads to stronger mobility.