Characterizing phase transitions in 2D Repulsive Random Organization

Random organization models of monodisperse spherical particles have been shown to undergo an absorbing state transition, exhibiting behavior characteristic of the Manna universality class. Here, we study the random organization model in 2D with the addition of repulsive displacements between particles. We show that the introduction of repulsive displacements results in three distinct phases: an absorbing inactive phase, a disordered active phase, as well as a polycrystalline active phase which is not observed in the absence of repulsion. Through a comparison of hyperuniformity and critical exponents, we show that the absorbing-to-disordered and absorbing-to-polycrystalline transitions belong to different universality classes, with only the former belonging to the Manna universality class. We compare the behavior of the two active phases using a computable information density approach and demonstrate how particle dynamics differ in each phase.