Demonstration of a controllable three-dimensional Brownian motor in symmetric potentials

P. Sjölund¹, S. J. H. Petra¹, C. M. Dion¹, S. Jonsell¹, M. Nylén¹, L. Sanchez-Palencia², and A. Kastberg¹

¹Department of Physics, Umeå University, SE-901 87 Umeå, Sweden
²Laboratoire Charles Fabry, Institut d'Optique Théorique et Appliquée, Université Paris-Sud XI, F-91403 Orsay cedex, France

We demonstrate a Brownian motor, based on cold atoms in optical lattices, where isotropic random fluctuations are rectified in order to induce controlled atomic motion in arbitrary directions. In contrast to earlier demonstrations of ratchet effects, our Brownian motor operates in potentials that are spatially and temporally symmetric, but where spatiotemporal symmetry is broken by a phase shift between the potentials and asymmetric transfer rates between them. The Brownian motor is demonstrated in three dimensions and the noise-induced drift is controllable in our system.

This article has been published in The Physical Review Letters 96, 190602 (2006) and may be found at http://publish.aps.org/abstract/PRL/v96/e190602.

Download reprint [pdf].

Back to Claude Dion's list of publications.