Physical Review A
Magnetic guide for neutral atoms
James T. Richmond, B. P. Cantwell, Síle Nic Chormaic, David Lau, A. M. Akulshin, Geoffrey I. Opat
Abstract
A solenoid consisting of two interwound helical coils carrying equal but opposite currents can act as a guide for neutral atoms. In this paper we develop the theory of such a guide and report on its performance in guiding laser-cooled cesium atoms. Our guide is a useful tool for transporting cooled atoms since it prevents ballistic expansion of the atomic cloud after it is released from a magneto-optical trap. In contrast to atom-guide designs using permanent magnets, our guide can be switched off by switching the currents; hence it can be placed close to a magnetic trap without adversely affecting the trapping efficiency. One of the unique features of this guide is that, except in the immediate neighborhood of the walls of the guide, the atoms are not magnetically perturbed to any appreciable extent by the guide field. This opens up the possibility of a system for cooling atoms.