Using a tightly focused beam of light as optical tweezers, researchers have confined a single neutral atom for long enough to cool it to its lowest-energy quantum state, a requirement for many quantum-computing applications.

Researchers have previously cooled charged atoms in a similar way, but uncharged atoms may be more appealing for use in quantum devices because they do not interact with electric fields. Cindy Regal and her collaborators at JILA, a joint research institute of the US National Institute of Standards and Technology and the University of Colorado at Boulder, first used optical tweezers to trap an individual rubidium atom. Then, using a laser-based technique called Raman sideband cooling, they cooled the atom to its near-motionless ground state.

Phys. Rev. X 2, 041014 (2012)