To determine the fluid velocity v and external-potential intensity V$_{0}$ we examine the effective external potential, defined as i.e., the sum of external periodic potential and a fictitious potential representing the constant friction force acting on particles (see Fig. 1(b)). If bvd$_{0}$ ≫ V$_{0}$ , particles do not feel the periodic potential, while if bvd$_{0}$ ≪ V$_{0}$ particle hopping is essentially unbiased. Let Δ E$_{G}$ (Δ E$_{P}$ ) denote the difference between a given maximum of V$_{eff}$ and the first minimum to the right (left) of this maximum. In this way, Δ E$_{G}$ (Δ E$_{P}$ ) is the potential barrier separating a given potential minimum from its left (right) neighbor. A simple calculation shows that with such that the potential minima occur at x$_{j}$ = 2 jd$_{0}$ + x$_{0}$ , and maxima at y$_{j}$ = 2 jd$_{0}$ + 1 − x$_{0}$ for j an integer. Given Δ E$_{G}$ and Δ E$_{P}$ , we can determine x$_{0}$ , v and V$_{0}$ . We take Δ E$_{P}$ ∼ k$_{B}$T , and Δ E$_{G}$ ≫ k$_{B}$T , so that a particle has a finite rate of jumping to the well on the right, and virtually no chance of jumping in the opposite direction. A good correspondence with lattice TASEP is obtained using Δ E$_{G}$ = 20 k$_{B}$T and Δ E$_{P}$ = 2 k$_{B}$T . For these values we have, To maintain the interparticle repulsion in the presence of the external potential, we must take U$_{0}$ substantially greater than V$_{0}$ . On the other hand, very large values 8 v = 2 . 1974 µ m/s V$_{0}$ = 4 . 5680 k$_{B}$T x$_{0}$ = 0 . 2158 µ m . (14) x$_{0}$ = d$_{0}$ π sin − 1 ( bvd$_{0}$ πV$_{0}$ ) , (13) Δ E$_{G}$ − Δ E$_{P}$ = 2 bvd$_{0}$ , Δ E$_{G}$ + Δ E$_{P}$ = 4 V$_{0}$ cos( πx$_{0}$/d$_{0}$ ) + 4 bvx$_{0}$ , (12) V$_{eff}$ = − V$_{0}$ cos ( π x d$_{0}$ ) − bvx, (11)