Traffic Jams, Gliders, and Bands in the Quest for Collective Motion of Self-Propelled Particles

Abstract

We study a simple swarming model on a two-dimensional lattice where the self-propelled particles exhibit a tendency to align ferromagnetically. Volume exclusion effects are present: particles can only hop to a neighboring node if the node is empty. Here we show that such effects lead to a surprisingly rich variety of self-organized spatial patterns. As particles exhibit an increasingly higher tendency to align to neighbors, they first self-segregate into disordered particle aggregates. Aggregates turn into traffic jams. Traffic jams evolve toward gliders, triangular high density regions that migrate in a well-defined direction. Maximum order is achieved by the formation of elongated high density regions--bands--that transverse the entire system. Numerical evidence suggests that below the percolation density the phase transition associated with orientational order is of first order, while at full occupancy it is of second order.

Additivity, density fluctuations, and nonequilibrium thermodynamics for active Brownian particles

“…They have been realized in experiments [16] and intensively studied through simulations and theories [17][18][19][20][21][22][23][24][25]; for reviews, see [26,27]. These particles propel themselves by converting chemical energy to mechanical one, which is continually dissipated to the medium.…”

Equilibrium and dynamical behavior in the Vicsek model for self-propelled particles under shear

“…Our rule is simpler than but related to that used in the models in [31,32], where the dependence of the velocity on the density is continuous. In a real suspension of self-propelled active particles or bacteria, a densitydependent speed may be due to steric interactions [33] or to biochemical signalling [31].…”

Entropic Ratchet transport of interacting active Brownian particles

“…However, active matters in biological and physical systems have been studied theoretically and experimentally [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. The kinetics of active particles moving in periodic structures could exhibit peculiar behaviors.…”