Strong Mobility in Weakly Disordered Systems
E. Ben-Naim and P.L. Krapivsky
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 $t$, $\sigma\sim
(\epsilon\,t)^{2/3}$, where $\epsilon$ is the disorder
strength. Without disorder the particle displacement is sub-diffusive,
$\sigma\sim t^{1/4}$, 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.
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