  Self-propelled particles form various patterns through dynamic
self-organization like swarming. Here, we explore numerically a new mechanism
of mono-polar clustering of self-propelled particles by controlling left-right
asymmetry of motility with bidirectional alignment. We apply two types of
torque to the particles, resulting in rotation of global orientation and
clustering depending on the balance of the two torque. The particles in global
orientation exhibit bi-polar motion, while the clusters predominantly exhibit
mono-polar motion. This mono-polar cluster actually recapitulates the rotating
swarms observed in a microtubule gliding assay.
