Strong Mobility in Weakly Disordered Systems

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 σ grows superdiffusively with time t, σ∼(ϵt)^2/3, where ϵ is the disorder strength. Without disorder the particle displacement is subdiffusive, σ∼t^1/4, and therefore disorder strongly enhances particle mobility. We explain this effect using scaling arguments, and verify the theoretical predictions through numerical simulations. Also, the simulations show that regardless of disorder strength, disorder leads to stronger mobility over an intermediate time regime.