Active matter commensuration and frustration effects on periodic substrates

We show that self-driven particles coupled to a periodic obstacle array exhibit active matter commensuration effects that are absent in the Brownian limit. As the obstacle size is varied for sufficiently large activity, a series of commensuration effects appear in which the motility induced phase separation produces commensurate crystalline states, while for other obstacle sizes we find frustrated or amorphous states. The commensuration effects are associated with peaks in the amount of sixfold ordering and the maximum cluster size. When a drift force is added to the system, the mobility contains peaks and dips similar to those found in transport studies for commensuration effects in superconducting vortices and colloidal particles.

Automated summary

Self-driven particles coupled to a periodic obstacle array exhibit commensuration effects, producing commensurate crystalline states as well as frustrated or amorphous states depending on the obstacle sizes. These effects are associated with peaks in sixfold ordering and maximum cluster size, and exhibit peaks and dips in mobility when a drift force is introduced, similar to studies on superconducting vortices and colloidal particles.