Berlin 2012 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 27: Transport and Anomalous Diffusion

DY 27.3: Vortrag

Donnerstag, 29. März 2012, 15:15–15:30, MA 004

Fractional Brownian ratchets — •Igor Goychuk¹ and Vasyl Kharchenko^1,2 — ¹Institute of Physics, University of Augsburg, Universitätstr. 1, D-86135 Augsburg, Germany — ²Institute of Applied Physics, 58 Petropavlovskaya str., 40030 Sumy, Ukraine

We study fluctuating tilt Brownian ratchets based on fractional subdiffusion in sticky viscoelastic media characterized by a power law memory kernel [1]. Unlike the normal diffusion case the rectification effect vanishes in the adiabatically slow modulation limit and optimizes in a driving frequency range [2]. It is also shown [3] that anomalous rectification effect is maximal (stochastic resonance effect) at optimal temperature and can exhibit a surprisingly good quality. Moreover, subdiffusive current can flow in the counter-intuitive direction upon a change of temperature or driving frequency. The dependence of anomalous transport on load exhibits a remarkably simple universality.

Support of this work by the DFG, grant GO 2052/1-1 is gratefully acknowledged.

[1] I. Goychuk, Phys. Rev. E 80, 046125 (2009); Adv. Chem. Phys. 150, 187–253 (2012); [2] I. Goychuk, Chem. Phys. 375, 450 (2010); [3] I. Goychuk and V. Kharchenko, arXiv:1111.4833[cond-mat.stat-mech] (2011).