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DY: Fachverband Dynamik und Statistische Physik
DY 26: Brownian Motion, Transport and Anomalous Diffusion
DY 26.5: Vortrag
Dienstag, 17. März 2020, 11:00–11:15, HÜL 186
Influence of fractional hydrodynamic memory on superdiffusion and supertransport in tilted washboard potentials — •Igor Goychuk — Friedrich-Alexander Universität Erlangen-Nürnberg — Universität Augsburg, Germany
Diffusion in tilted washboard potentials can paradoxically exceed free normal diffusion [1]. The effect becomes much stronger in the underdamped case due to inertial effects [2]. What happens upon inclusion of usually neglected fractional hydrodynamics memory effects (Basset-Boussinesq frictional force), which result in a heavy algebraic tail of the velocity autocorrelation function of the potential-free diffusion making it transiently superdiffusive? Will a giant enhancement of diffusion become even stronger, and the transient superdiffusion last even longer? These are the basic questions which we answer [3] based on an accurate numerical investigation. We show that a resonance-like enhancement of normal diffusion becomes indeed much stronger and sharper. Moreover, a long-lasting transient regime of superdiffusion, including Richardson-like diffusion, ⟨ δ x2(t)⟩∝ t3 and ballistic supertransport, ⟨ δ x(t)⟩∝ t2, is revealed.
[1] P. Reimann, C. Van den Broeck, H. Linke, P. Hänggi, J. M. Rubi, and A. Perez-Madrid, Phys. Rev. Lett. 87, 010602 (2001).
[2] I. G. Marchenko and I. I. Marchenko, EPL 100, 50005 (2012); B. Lindner and I. M. Sokolov, Phys. Rev. E 93, 042106 (2016).
[3] I. Goychuk, Phys. Rev. Lett. 123, 180603 (2019), Editors’ Suggestion.