title: Transient anomalous diffusion in periodic systems: ergodicity, symmetry breaking and velocity relaxation.
abstract: We study far from equilibrium transport of a periodically driven inertial Brownian particle moving in a periodic potential. As detected for a SQUID ratchet dynamics, the mean square deviation of the particle position from its average may involve three distinct intermediate, although extended diffusive regimes: initially as superdiffusion, followed by subdiffusion and finally, normal diffusion in the asymptotic long time limit. Even though these anomalies are transient effects, their lifetime can be many, many orders of magnitude longer than the characteristic time scale of the setup and turns out to be extraordinarily sensitive to the system parameters like temperature or the potential asymmetry. In the paper we reveal mechanisms of diffusion anomalies related to ergodicity of the system, symmetry breaking of the periodic potential and ultraslow relaxation of the particle velocity towards its steady state. Similar sequences of the diffusive behaviours could be detected in various systems including, among others, colloidal particles in random potentials, glass forming liquids and granular gases.
authors: Institute of Physics, University of Silesia, 40-007 Katowice, Poland.|Silesian Center for Education and Interdisciplinary Research, University of Silesia, 41-500 Chorzów, Poland.
authors: Jakub
authors: J
authors: Spiechowicz
authors: Institute of Physics, University of Silesia, 40-007 Katowice, Poland.|Silesian Center for Education and Interdisciplinary Research, University of Silesia, 41-500 Chorzów, Poland.
authors: Jerzy
authors: J
authors: Łuczka
authors: Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.|Nanosystems Initiative Munich, Schellingstr, 4, D-80799 Műnchen, Germany.
authors: Peter
authors: P
authors: Hänggi