Ratchets from the cold: Brownian motors with cold atoms in optical lattices

Abstract

Brownian motors, or ratchets, are devices which 'rectify' Brownian motion, that is, they can generate a current of particles out of unbiased fluctuations. The present article reviews recent experimental realizations of ratchets employing cold atoms in optical lattices. This is quite an unusual system for a Brownian motor as there is not a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields. Such a system has allowed us to explore a number of fundamental features of ratchets. m artist impression of the ratchet. © antoine tisserandArticle available at

Tunable transport with broken space–time symmetries

“…The rocking ratchet set-up, used in the experiments with cold atom ratchets [50,39,25], corresponds to a simple-harmonic potential force,…”

Note: Design and implementation of a home-built imaging system with low jitter for cold atom experiments

“…In experiments with optical lattices and ratchets, the camera tracks changes in the position of the center of mass, and the width, of the cold atom cloud. 3 It is clearly of interest to many experimental groups to construct a fast, low-jitter CCD camera system to image the atoms. We have chosen to follow previous literature and modify an inexpensive versatile astronomy camera 4 which has the required sensitivity to detect faint light signals.…”

“…5 is now obsolete. Our home-built system's performance rivals expensive new "black box" commercial systems, 3,6 while allowing the experimenter some extra flexibility inherent to a home-built setup, e.g, switching between different cameras. Table I summarizes features of home-built and commercial imaging systems.…”