Figure 4.

Diffusion constant D plotted against the number N of sites per cycle by keeping the entropy $\sigma$ per cycle and velocity v constant for $N\ge 3$. We chose the produced entropy per cycle to be $\sigma /k_B=10$. The red line is the value $D(N\to \infty )\to v2\pi R{k}_B/\sigma$ in the limit of $N\to \infty$.