German Laser Emits Matter Waves

MUNICH, Germany, March 17 -- Scientists at the Max Planck Institute for Quantum Optics in Garching and the University of Munich have developed a laser that emits a continuous beam of matter waves instead of light. The researchers have imaged the shadow cast by the laser's beam, which shows a pencil-like beam containing about half a million rubidium atoms accelerated downward by gravity.
In the Munich experiment, a dilute gas of rubidium atoms is captured in a sophisticated low-power magnetic trap and cooled down to reach Bose-Einstein condensation. With the help of a radiofrequency field, the scientists flip the atomic spin so that atoms are allowed to escape from the magnetic trap. In a vacuum, the atoms are accelerated by gravity to form a parallel beam of coherent matter waves. The Munich group claims to be the first to produce a continuous matter wave beam which can be maintained for a tenth of a second.