  Rectified transport of active ellipsoidal particles is numerically
investigated in a two-dimensional asymmetric potential. The out-of-equilibrium
condition for the active particle is an intrinsic property, which can break
thermodynamical equilibrium and induce the directed transport. It is found that
the perfect sphere particle can facilitate the rectification, while the
needlelike particle destroys the directed transport. There exist optimized
values of the parameters (the self-propelled velocity, the torque acting on the
body) at which the average velocity takes its maximal value. For the
ellipsoidal particle with not large asymmetric parameter, the average velocity
decreases with increasing the rotational diffusion rate, while for the
needlelike particle (very large asymmetric parameter), the average velocity is
a peaked function of the rotational diffusion rate. By introducing a finite
load, particles with different shapes (or different self-propelled velocities)
will move to the opposite directions, which is able to separate particles of
different shapes (or different self-propelled velocities).
