Abstract
Progress in atomic, optical and quantum science1,2 has led to rapid improvements in atomic clocks. At the same time, atomic clock research has helped to advance the frontiers of science, affecting both fundamental and applied research. The ability to control quantum states of individual atoms and photons is central to quantum information science and precision measurement, and optical clocks based on single ions have achieved the lowest systematic uncertainty of any frequency standard3,4,5. Although many-atom lattice clocks have shown advantages in measurement precision over trapped-ion clocks6,7, their accuracy has remained 16 times worse8,9,10. Here we demonstrate a many-atom system that achieves an accuracy of 6.4âÃâ10â18, which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude. By systematically evaluating all known sources of uncertainty, including in situ monitoring of the blackbody radiation environment, we improve the accuracy of optical lattice clocks by a factor of 22. This single clock has simultaneously achieved the best known performance in the key characteristics necessary for consideration as a primary standardâstability and accuracy. More stable and accurate atomic clocks will benefit a wide range of fields, such as the realization and distribution of SI units11, the search for time variation of fundamental constants12, clock-based geodesy13 and other precision tests of the fundamental laws of nature. This work also connects to the development of quantum sensors and many-body quantum state engineering14 (such as spin squeezing) to advance measurement precision beyond the standard quantum limit.
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Acknowledgements
We thank M. Martin, M. Swallows, E. Arimondo, J. L. Hall, T. Pfau, and W. D. Phillips for discussions and H. Green for technical assistance. This research is supported by the National Institute of Standards and Technology, the Defense Advanced Research Projects Agencyâs QuASAR Program, and the NSF PFC. M.B. acknowledges support from the National Defense Science and Engineering Graduate fellowship programme. S.L.C. and M.B. acknowledge support from the NSF Graduate Fellowship. Any mention of commercial products does not constitute an endorsement by NIST.
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B.J.B., T.L.N., J.R.W., S.L.C., M.B., X.Z., W.Z., S.L.B. and J.Y. conceived, designed and carried out the experiments mentioned in this manuscript. All authors discussed the results and contributed to the manuscript.
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Bloom, B., Nicholson, T., Williams, J. et al. An optical lattice clock with accuracy and stability at the 10â18 level. Nature 506, 71â75 (2014). https://doi.org/10.1038/nature12941
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DOI: https://doi.org/10.1038/nature12941