Binary mixtures of hard sphere active Brownian particles

We computationally study the phase behavior and dynamics of a binary mixture of active Brownian particles, where each ‘species’ is distinguished by its persistence of motion (effectively two species: fast, slow active particles). We find that our binary active system demonstrates motility-induced phase separation (analogous to monodisperse active systems) depending on the activity ratio, and concentration of each species. We observe a variety of steady states, which emerge as we vary the ratio of constituent particle activity, ranging from volatile partially segregated steady-state clusters, prone to fission, to a homogenously distributed, relatively stable, single cluster. We extend current theory for passive-active mixtures to account for active-active mixtures as well.