(473h) Active Phase Separation in Binary Population of Polar Microswimmers

We investigate the collective dynamics of a binary population of polar microswimmers with off-center interaction sites in an unbounded domain under periodic boundary conditions. The two species differ in their intrinsic speeds and relative population fractions, yet both interact through the same alignment mechanism. Despite these differences, the system self-organizes into a globally polar swarm. Within this polar phase, we observe spontaneous active phase separation: the fast and slow swimmers segregate into thread-like structures and distinct domains aligned with the direction of collective motion. This emergent segregation arises solely from differences in motility and crowding effects, without any explicit attractive interactions. Our results highlight a robust mechanism of active phase separation driven by polarity and speed disparity, offering new insights into the design and control of synthetic active mixtures and heterogeneous microswimmer systems. We acknowledge support from the National Science Foundation CAREER award, grant number CBET-2238915.