Eur. Phys. J. B 25, 345-350 (2002)
https://doi.org/10.1140/epjb/e20020039

Directed transport of an asymmetric particle pair induced by non-equilibrium conditions

Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden, Germany

Corresponding author: ^a porto@mpipks-dresden.mpg.de

Received: 17 August 2001
Revised: 11 October 2001
Published online: 15 February 2002

Abstract

The hopping motion of a classical bounded pair of two particles along a chain is investigated. It is shown that in the asymmetric case of the system dynamics including excited states which differ from the respective ground states by the barrier to be overcome by one of the two particles, the over- and underpopulation of these excited states leads to a directed motion of the particle pair. Thereby, overpopulation results in one direction of motion, whereas underpopulation results in the opposite direction, and the mean velocity is determined by the amount of over-resp. underpopulation. For small deviations from equilibrium, the system exhibits linear response well known from other ratchet-type models. Possible generalizations and applications are discussed.