  Rectification and diffusion of non-interacting self-propelled particles is
numerically investigated in a two-dimensional corrugated channel. From
numerical simulations, we obtain the average velocity and the effective
diffusion coefficient. It is found that the self-propelled particles can be
rectified by the self-propelled velocity. There exist optimal values of the
parameters (the self-propelled velocity, the translational diffusion constant,
and the height of the potential) at which the average velocity takes its
maximal value. There exists an optimal translational diffusion at which the
effective diffusion constant is maximal. The self-propelled velocity can
strongly increase the effective diffusion, while the large rotational diffusion
rate can strongly suppress the effective diffusion.
