Pattern Formation and Transport for Externally Driven Active Matter on Periodic Substrates

Abstract

We investigate the transport of interacting active run-and-tumble particles moving under an external drift force through a periodic array of obstacles for increasing drive amplitudes. For high activity where the system forms a motility induced phase separated state, there are several distinct dynamic phases including a low drive pinned cluster phase, an intermediate uniform fluid, and a higher drive stripe crystal state. The transitions between the phases are correlated with signatures in the transport curves, differential mobility, and power spectra of the velocity fluctuations. In contrast, in the low activity regime the transport curves and power spectra undergo little change as a function of drive. We argue that in the high activity limit, the behavior is similar to that of driven solids on periodic substrates, while in the low activity limit the system behaves like a driven fluid.

6 pages, 6 postscript figures

References in corpus (7)

• Motility-Induced Phase Separation
• Observation of Vortex Pinning in Bose-Einstein Condensates
• Transport of active ellipsoidal particles in ratchet potentials
• Collective Directional Locking of Colloidal Monolayers on a Periodic Substrate
• Solitons in overdamped Brownian dynamics
• Deflection of phototactic microswimmers through obstacle arrays
• Future Directions for Active Matter on Ordered Substrates

Cited by in corpus (3)

• Active particles confined in deformable droplets
• Polarization and dynamic phases of aligning active matter in periodic obstacle arrays
• Macrotransport of active particles in periodic channels and fields: rectification and dispersion