Direct Comparison of Distant Optical Lattice Clocks at the $10^{-16}$ Uncertainty

Abstract

Fiber-based remote comparison of ${}^{87}$Sr lattice clocks in 24 km distant laboratories is demonstrated. The instability of the comparison reaches $5\times 10^{-16}$ over an averaging time of 1000 s, which is two orders of magnitude shorter than that of conventional satellite links and is limited by the instabilities of the optical clocks. By correcting the systematic shifts that are predominated by the differential gravitational redshift, the residual fractional difference is found to be $(1.0\pm 7.3)\times 10^{-16}$, confirming the coincidence between the two clocks. The accurate and speedy comparison of distant optical clocks paves the way for a future optical redefinition of the second.

References in corpus (7)

• Sr lattice clock at 1x10^{-16} fractional uncertainty by remote optical evaluation with a Ca clock
• Long-distance frequency transfer over an urban fiber link using optical phase stabilization
• The absolute frequency of the 87Sr optical clock transition
• Lattice Induced Frequency Shifts in Sr Optical Lattice Clocks at the $10^{-17}$ Level
• Improved frequency measurement of a one-dimensional optical lattice clock with a spin-polarized fermionic ${}^{87}$Sr isotope
• Measuring the frequency of a Sr optical lattice clock using a 120-km coherent optical transfer
• An Optical Lattice Clock with Spin-polarized 87Sr Atoms

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