title: Noise-induced vortex reversal of self-propelled particles.
abstract: We report an interesting phenomenon of noise-induced vortex reversal in a two-dimensional system of self-propelled particles (SPPs) with soft-core interactions. With the aid of forward flux sampling, we analyze the configurations along the reversal pathway and thus identify the mechanism of vortex reversal. We find that the reversal exhibits a hierarchical process: those particles at the periphery first change their motion directions, and then more inner layers of particles reverse later on. Furthermore, we calculate the dependence of the average reversal rate on noise intensity D and the number N of SPPs. We find that the rate decreases exponentially with the reciprocal of D. Interestingly, the rate varies nonmonotonically with N and a local minimal rate exists for an intermediate value of N.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscales & Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Hanshuang
authors.initials: H
authors.lastname: Chen
authors.forename: Zhonghuai
authors.initials: Z
authors.lastname: Hou
mesh_terms: D000465:Algorithms; D001703:Biophysics / Q000379:methods*; D003198:Computer Simulation; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D009038:Motion; D009068:Movement; D009622:Noise; D011336:Probability; D013997:Time Factors