Rectified transport of self-propelled particles: the role of alignment interaction

We study the rectified efficiency of self-propelled particles in a confined structure in the presence of ferromagnetic (polar) and nematic alignments. It is found that purely polar alignment can greatly facilitate the rectification, and the rectified efficiency can even be up to 1. However, the purely nematic alignment suppresses the rectification for large self-propulsion speed and slightly facilitates the rectification for small self-propulsion speed. With an increase in the relative weight of polar interactions, the rectified efficiency is suddenly increased from 0–1, with the jump depending on the order switching from nematic to polar. From the point of view of dynamic ordering, we can conclude that the perfect polarly ordered phase will cause the maximal rectified efficiency, while the genuine apolarly ordered phase will suppress the rectification.