Caporusso, Claudio B.Digregorio, PasqualeLevis, DemianCugliandolo, Leticia F.Gonnella, Giuseppe2020-11-242020-11-242020-11-242020-10-2310.1103/PhysRevLett.125.178004https://infoscience.epfl.ch/handle/20.500.14299/173591WOS:000582242700014As a result of nonequilibrium forces, purely repulsive self-propelled particles undergo macrophase separation between a dense and a dilute phase. We present a thorough study of the ordering kinetics of such motility-induced phase separation (MIPS) in active Brownian particles in two dimensions, and we show that it is generically accompanied by microphase separation. The growth of the dense phase follows a law akin to the one of liquid-gas phase separation. However, it is made of a mosaic of hexatic microdomains whose size does not coarsen indefinitely, leaving behind a network of extended topological defects from which microscopic dilute bubbles arise. The characteristic length of these finite-size structures increases with activity, independently of the choice of initial conditions.Physics, MultidisciplinaryPhysicstext::journal::journal article::research article