Ratchet transport of overdamped particles in superimposed driven lattices

Ratchet transport of overdamped particles is investigated in superimposed driven lattices using Langevin dynamics simulations. It is found that noise can strongly affect the transport of the particles. When lattices driving dominates the transport, the noise acts as a disturbance of the directed transport and slows down the average velocity of the particles. When the driving phase has less impact on particle transport, Gaussian white noise can play a positive role. By simply modulating these two parameters, we can control efficiency and the direction of the directed currents.