For the past 50 years, atomic standards based on the frequency of the cesium ground-state hyperfine transition have been the most accurate time pieces in the world. We now report a comparison between the cesium fountain standard NIST-F1, which has been evaluated with an inaccuracy of about 4×10-16, and an optical frequency standard based on an ultraviolet transition in a single, laser-cooled mercury ion for which the fractional systematic frequency uncertainty was below 7.2×10-17. The absolute frequency of the transition was measured versus cesium to be 1 064 721 609 899 144.94 (97) Hz, with a statistically limited total fractional uncertainty of 9.1×10-16, the most accurate absolute measurement of an optical frequency to date.
Single-Atom Optical Clock with High Accuracy / W. H., Oskay; S. A., Diddams; E. A., Donley; T. M., Fortier; T. P., Heavner; L., Hollberg; W. M., Itano; S. R., Jefferts; M. J., Delaney; K., Kim; Levi, Filippo; T. E., Parker; AND J. C., Bergquist. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 97:(2006). [10.1103/PhysRevLett.97.020801]
Single-Atom Optical Clock with High Accuracy
LEVI, FILIPPO;
2006
Abstract
For the past 50 years, atomic standards based on the frequency of the cesium ground-state hyperfine transition have been the most accurate time pieces in the world. We now report a comparison between the cesium fountain standard NIST-F1, which has been evaluated with an inaccuracy of about 4×10-16, and an optical frequency standard based on an ultraviolet transition in a single, laser-cooled mercury ion for which the fractional systematic frequency uncertainty was below 7.2×10-17. The absolute frequency of the transition was measured versus cesium to be 1 064 721 609 899 144.94 (97) Hz, with a statistically limited total fractional uncertainty of 9.1×10-16, the most accurate absolute measurement of an optical frequency to date.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
