Three years ago in a Colorado laboratory, scientists realised a long-
standing dream, bringing the quantum world closer to the one of everyday experience
In June 1995 our research group at the Joint Institute for Laboratory Astrophysics (now called JILA) in Boulder, Colo., succeeded in creating a minuscule but marvellous droplet. By cooling 2,000 rubidium atoms to a temperature less than 100 billionths of a degree above absolute zero (100 billionths of a degree kelvin), we caused the atoms to lose for a full 10 seconds their individual identities and behave as though they were a single "superatom." The atoms' physical properties, such as their motions, became identical to one another.This Bose-Einstein condensate (BEC), the first observed in a gas, can be thought of as the matter counterpart of the laser-except that in the condensate it is atoms, rather than photons, that dance in perfect unison.
