Eur. Phys. J. D 35, 125-133 (2005)
https://doi.org/10.1140/epjd/e2005-00177-6

Long distance magnetic conveyor for precise positioning of ultracold atoms

¹ Max-Planck-Institut für Quantenoptik and Ludwig-Maximilians-Universität München, Schellingstrasse 4, 80799 München, Germany
² Laboratoire Kastler Brossel, Département de Physique de l'École Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France

Corresponding author: ^a jakob.reichel@lkb.ens.fr

Received: 2 May 2005
Published online: 28 June 2005

Abstract

We describe a chip-based magnetic conveyor that transports ultracold atoms with high positioning accuracy over long distances, into an interaction region which is well separated from the magneto-optical trap and gives good optical access to the atoms. The conveyor can work in two different modes, with or without external bias field. The transport potential is generated by a two-layer conductor pattern, enabling a significantly smoother transport than our earlier single-layer conveyor. This is confirmed by numerical field calculations, using an optimization procedure that minimizes shape deformations as well as deviations from the linear transport path. We experimentally demonstrate the use of this conveyor in the mode with external bias field, transporting a cloud of cold atoms over a linear distance of 6 cm and a total distance of 24 cm. We also describe an on-chip quadrupole trap that can be rotated by . This trap is used to remove design constraints on the orientation of the laser beams in the surface magneto-optical trap. The long-distance conveyor is a versatile tool for experiments with trapped cold atoms, and can achieve sub-micrometric positioning precision. Possible applications of this tool are discussed.