Finite size scaling and universality classes of one-dimensional active matter interface

Abstract A one-dimensional active interface is studied by confining active Brownian particles moving in two dimensions between two rigid parallel walls. The finite size scale behaviour of height fluctuations for this interface shows that at high activity values, the active interface progresses through three different scaling regimes of growth of height fluctuations. At large times, directly evaluated growth ( β ) and roughness ( α ) exponents confirms the presence of universality class for smoothening of active interface, whereas behaviour of Edwards-Wilkinson universality class is recovered at small timescales. Roughness exponent and growth exponent lead to best collapse of interface width data for the intermediate regime. Orientations of particles, which play a central role during interface formation, are shown to exhibit different behaviour during different growth regimes of height fluctuations.