Delivery of Single Atoms on Demand

Delivery of single atoms on demand is now possible. Physicists at the University of Bonn hold cold cesium atoms in a magneto-optic trap, but can shuttle the neutral atoms, one a time, with great control over distances up to a centimeter by shifting an additional laser-light interference pattern serving as local potential well. This kind of conveyor belt for atoms is expected to be of help in various quantum entanglement experiments or as part of an atomic shift register. (Kuhr et al., Science, 13 July 2001; kuhr@iap.uni-bonn.de.)