Demonstration of 4.8 × 10⁻¹⁷ stability at 1 s for two independent optical clocks

authored by

E. Oelker, R. B. Hutson, C. J. Kennedy, L. Sonderhouse, T. Bothwell, A. Goban, D. Kedar, C. Sanner, J. M. Robinson, G. E. Marti, D. G. Matei, T. Legero, M. Giunta, R. Holzwarth, F. Riehle, U. Sterr, J. Ye

Abstract

Optical atomic clocks require local oscillators with exceptional optical coherence owing to the challenge of performing spectroscopy on their ultranarrow-linewidth clock transitions. Advances in laser stabilization have thus enabled rapid progress in clock precision. A new class of ultrastable lasers based on cryogenic silicon reference cavities has recently demonstrated the longest optical coherence times to date. Here we utilize such a local oscillator with two strontium (Sr) optical lattice clocks to achieve an advance in clock stability. Through an anti-synchronous comparison, the fractional instability of both clocks is assessed to be 4.8×10-17∕τ for an averaging time τ (in seconds). Synchronous interrogation enables each clock to average at a rate of 3.5×10-17∕τ, dominated by quantum projection noise, and reach an instability of 6.6 × 10⁻¹⁹ over an hour-long measurement. The ability to resolve sub-10⁻¹⁸-level frequency shifts in such short timescales will affect a wide range of applications for clocks in quantum sensing and fundamental physics.

External Organisation(s)

University of Colorado Boulder
Stanford University
National Metrology Institute of Germany (PTB)
Horia Hulubei National Institute of Physics and Nuclear Engineering
Menlo Systems GmbH
Max Planck Institute of Quantum Optics (MPQ)

Type

Article

Journal

Nature photonics

Volume

13

Pages

714-719

No. of pages

6

ISSN

1749-4885

Publication date

01.10.2019

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Atomic and Molecular Physics, and Optics

Electronic version(s)

https://doi.org/10.1038/s41566-019-0493-4 (Access: Unknown)