Ratchet transport of overdamped particles in superimposed driven lattices
Huang Shu-Na, Zhu Wei-Jing, Huang Xiao-Qun, Ai Bao-Quan, Li Feng-Guo
       

Average velocity V as a function of particle number N at ϕ=π/2, d=π, D0 = 0.1, and ω=1.0.