Cooperative two-dimensional directed transport

¹ Department of Physics and the Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Studies, Beijing Normal University - Beijing 100875, China
² Queen's College, City University of New York - New York, NY 11367, USA
³ College of Engineering and Information Science, Huaqiao University - Xiamen Fujian 361021, China

^a zgzheng@bnu.edu.cn

Received: 11 August 2010
Accepted: 18 October 2010

Abstract

A mechanism for the cooperative directed transport in two-dimensional ratchet potentials is proposed. With the aid of mutual couplings among particles, coordinated unidirectional motion along the ratchet direction can be achieved by transforming the energy from the transversal rocking force (periodic or stochastic) to the work in the longitude direction. Analytical predictions on the relation between the current and other parameters for the ac-driven cases are given, which are in good agreement with numerical simulations. Stochastic driving forces can give rise to the resonant directional transport. The effect of the free length, which has been explored in experiments on the motility of bipedal molecular motors, is investigated for both the single- and double-channel cases. The mechanism and results proposed in this letter may both shed light on the collective locomotion of molecular motors and open ways on studies in two-dimensional collaborative ratchet dynamics.