Abstract
The first frequency standard based on laser-cooled atoms is reported. Beryllium atomic ions were stored in a Penning trap and cooled by radiation pressure from a laser. The frequency of the ground-state hyperfine transition at its magnetic-field-independent point was determined to be 303 016 377.265 070 (57) Hz. The accuracy of a frequency standard referenced to this transition was comparable to the best frequency standards, which are based on cesium atomic beams.
- Received 5 December 1984
DOI:https://doi.org/10.1103/PhysRevLett.54.1000
©1985 American Physical Society