Volume 78, Number 5, June 2007
Article Number 50004
Number of page(s) 5
Section General
Published online 22 May 2007
EPL, 78 (2007) 50004
DOI: 10.1209/0295-5075/78/50004

Pulsating potential ratchet

P. Reimann and M. Evstigneev

Universität Bielefeld, Fakultät für Physik - Universitätsstr. 25, 33615 Bielefeld, Germany

received 7 February 2007; accepted in final form 20 April 2007; published June 2007
published online 22 May 2007

We consider Brownian motion in a periodic array of potential wells. The potential barriers between adjacent wells are spatially symmetric and pulsating periodically in time. While the modulation amplitude is the same for all barriers, the spatial symmetry is broken by sequentially alternating the respective pulsation frequencies among three different incommensurate values. The result is a net motion (ratchet effect), whose direction depends in an intriguing way on the detailed choice of parameters.

05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
02.50.Ey - Stochastic processes.
05.60.Cd - Classical transport.

© Europhysics Letters Association 2007