Transport of underdamped self-propelled particles in active density waves

Transport of underdamped self-propelled particles is numerically investigated in active density waves. From numerical simulations, it is found that the inertia can strongly affect the transport of self-propelled particles. By changing the wave speed or the friction coefficient, the average velocity can change its direction. The direction of the transport is also determined by the competition between the inertia effect and the traveling waves. Therefore, underdamped active particles can move in different directions and can be separated by suitably tailoring the parameters. (paper)