Europhys. Lett.
Volume 69, Number 4, February 2005
Page(s) 517 - 523
Section General
Published online 14 January 2005
Europhys. Lett., 69 (4), pp. 517-523 (2005)
DOI: 10.1209/epl/i2004-10391-2

Paradoxical directed diffusion due to temperature anisotropies

R. Eichhorn and P. Reimann

Universität Bielefeld, Fakultät für Physik Universitätsstraße 25, 33615 Bielefeld, Germany

received 29 October 2004; accepted 14 December 2004
published online 14 January 2005

An analytically tractable, but still experimentally realistic model dynamics is investigated, describing the Brownian motion of a particle in a "meandering" periodic potential landscape under the simultaneous influence of two different heat baths. The main characteristics of the resulting far-from-equilibrium environment is an anisotropy of the ambient temperature. When an external static force F is applied, the particle moves in the direction opposite to that force (absolute negative mobility), and this even for arbitrarily large forces |F|. Moreover, even when the "meandering" potential exhibits a broken spatial symmetry, no preferential direction of motion arises for F=0.

05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
05.60.-k - Transport processes.
02.50.Ey - Stochastic processes.

© EDP Sciences 2005