Nonlinear signal mixing in a ratchet deviceS. Savel'ev1, F. Marchesoni1, 2, P. Hänggi1, 3 and F. Nori1, 4
1 Frontier Research System, The Institute of Physical and Chemical Research (RIKEN) Wako-shi, Saitama, 351-0198, Japan
2 Dipartimento di Fisica, Università di Camerino - I-62032 Camerino, Italy
3 Institute of Physics, University of Augsburg - Universitätsstrasse 1 D-86135 Augsburg, Germany
4 Center for Theoretical Physics, Department of Physics, University of Michigan Ann Arbor, MI 48109-1120, USA
(Received 13 April 2004; accepted in final form 4 May 2004)
The nonlinear signal mixing of two, generally incommensurate, rectangular driving forces is used to control overdamped transport in Brownian ratchet devices. The interplay between the relative phase and the frequency ratio of the two driving forces is sufficient to generate an intriguing transport action that can be put to work to optimize shuttling and separation of particles in a variety of physical and technological applications. Analytic results for a striking multiple current reversal behavior are obtained for doubly rocked and rocked-pulsating Brownian ratchets. This tunable signal mixing can readily be implemented and exhibits an even richer behavior than those realized by the hard-to-implement, modifiable ratchet profiles.-1
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
05.60.Cd - Classical transport.
87.16.Uv - Active transport processes; ion channels.
© EDP Sciences 2004