Cool things to do with lasers

摘要

There has been dramatic progress recently in atomic physics. It is now routine at hundreds of laboratories worldwide to cool samples of atoms to microkelvin temperatures through a process called laser cooling. Bizarre as it may sound, it is possible to use lasers (which are usually associated with cutting and heating) to slow atoms from the jumbo-jet speed of a room temperature gas to a snail's pace. At these low temperatures exciting new physics is observed, and atoms are treated as waves. An overview of the physics principles that underlie this technique is given, as well as a few examples of recent progress in the emergent fields of atom optics and manipulation of coherent matter waves.