Transition from reversible to irreversible flow: Absorbing and depinning transitions in a sheared-vortex system

We provide evidence that a reversible to irreversible flow transition (RIT), as reported in driven colloidal particles, occurs in periodically sheared vortices in a Corbino-disk superconductor under increasing a displacement d of vortices per cycle. We determine a threshold displacement dc for RIT as the onset of flow noise. A relaxation time to reach the steady state diverges around dc, indicative of an absorbing transition from self-organized nonfluctuating (reversible) to fluctuating diffusing (irreversible) states. Our results strongly suggest that RIT is a universal phenomenon in driven interacting particle systems with quenched disorder. We also find evidence for a depinning transition with critical behavior similar to that of the absorbing transition in the same vortex system.