Interspecies clock comparison below $5 \times 10^{-18}$ uncertainty with a transportable clock

• URL: http://arxiv.org/abs/2608.01916v1
• Date: Mon, 03 Aug 2026 08:48:18 GMT
• Title: Interspecies clock comparison below $5 \times 10^{-18}$ uncertainty with a transportable clock
• Abstract summary: We report a measurement of the optical frequency ratio between the $2mathrmS_1/2(F0)$--$2mathrmF_7/2(F3)$ electric-octupole (E3) transition.<n>The result improves upon the previous best by more than a factor of three and is among the few that meet the requirements for interspecies clock comparisons.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We report a measurement of the optical frequency ratio between the $^2\mathrm{S}_{1/2}(F=0)$--${^2\mathrm{F}_{7/2}(F=3)}$ electric-octupole (E3) transition of $^{171}$Yb$^{+}$ and the $^1\mathrm{S}_0$--${^3\mathrm{P}_0}$ transition of $^{87}$Sr, $ν_{\mathrm{Yb}^{+}}/ν_\mathrm{Sr} = 1.495\,991\,618\,544\,900\,588\,1(65)$. Reaching a fractional uncertainty of $4.3 \times 10^{-18}$, this result improves upon the previous best by more than a factor of three and is among the few that meet the requirements for interspecies clock comparisons specified by the roadmap towards the redefinition of the SI second. The comparison is between a transportable optical lattice clock and a stationary single-ion clock. It spans a period of nearly two years, during which the transportable clock was intermittently operated off-campus. The ratio was reproducibly measured during four separate campaigns, which are consistent within their statistical uncertainties. The results demonstrate reproducible $10^{-18}$ level operation of the transportable clock and thus validate its application for chronometric geodesy and as a transfer standard for inter-institute clock comparisons, e.g., in the absence of optical fiber links.

Related papers

• On trace invariance and energy-dependent entanglement in muon decay [45.88028371034407]
  We revisit a proposed correction to the muon magnetic anomaly measurement.<n>We compare it with energy-binned scans reported by the Fermilab $g-2$ collaboration.
  arXiv  Detail & Related papers  (2026-08-19T12:06:54Z)
• Mesoscopic Fluctuations and Multifractality at and across Measurement-Induced Phase Transition [46.176861415532095]
  We explore statistical fluctuations over the ensemble of quantum trajectories in a model of two-dimensional free fermions.<n>Our results exhibit a remarkable analogy to Anderson localization, with $G_AB$ corresponding to two-terminal conductance.<n>Our findings lay the groundwork for mesoscopic theory of monitored systems, paving the way for various extensions.
  arXiv  Detail & Related papers  (2025-07-15T13:44:14Z)
• High-Stability Single-Ion Clock with $5.5\ imes10^{-19}$ Systematic Uncertainty [33.06992219558038]
  We report a single-ion optical atomic clock with fractional frequency uncertainty of $5.5times10-19$ and fractional frequency stability of $3.5 times10-16/sqrttau/mathrms$.<n>Based on quantum logic spectroscopy of a single $27$Al$+$ ion.
  arXiv  Detail & Related papers  (2025-04-17T16:32:15Z)
• High-accuracy multi-ion spectroscopy with mixed-species Coulomb crystals [0.17967666664330376]
  Operation with four clock ions reduces the instability from $1.6times10-15/sqrtt/ (1;mathrms)$ to $9.2times10-16/sqrtt/ (1;mathrms)$.<n>We derive a model for decay-related dead time during state preparation, which matches the observed scaling of instability with clock ion number $N$.
  arXiv  Detail & Related papers  (2025-01-16T15:40:45Z)
• An optical atomic clock using $4D_J$ states of rubidium [0.7499722271664147]
  We analyze an optical atomic clock using two-photon $5S_1/2 rightarrow 4D_J$ transitions in rubidium. Four one- and two-color excitation schemes to probe the fine-structure states $4D_3/2$ and $4D_5/2$ are considered in detail.
  arXiv  Detail & Related papers  (2024-06-13T17:40:06Z)
• $^{115}$In$^+$-$^{172}$Yb$^+$ Coulomb crystal clock with $2.5\times10^{-18}$ systematic uncertainty [0.1715290206208946]
  We present a scalable mixed-species Coulomb crystal clock based on the transition in $115$In$+$.<n>We demonstrate operation with four $115$In$+$ clock ions, which reduces the instability to $9.2times10-16/sqrttau/1;mathrms$.
  arXiv  Detail & Related papers  (2024-02-26T18:29:12Z)
• On the $O(\frac{\sqrt{d}}{T^{1/4}})$ Convergence Rate of RMSProp and Its Momentum Extension Measured by $\ell_1$ Norm [54.28350823319057]
  This paper considers the RMSProp and its momentum extension and establishes the convergence rate of $frac1Tsum_k=1T.<n>Our convergence rate matches the lower bound with respect to all the coefficients except the dimension $d$.<n>Our convergence rate can be considered to be analogous to the $frac1Tsum_k=1T.
  arXiv  Detail & Related papers  (2024-02-01T07:21:32Z)
• Long-distance chronometric leveling with a portable optical clock [0.0]
  We have measured the geopotential difference between two locations separated by $457mathrmkm$ by comparison of two optical lattice clocks via an interferometric fiber link.<n>The uncertainty of the chronometric geopotential difference is equivalent to an uncertainty of $27mathrmcm$ in height.
  arXiv  Detail & Related papers  (2023-09-26T14:12:07Z)
• Moments, Random Walks, and Limits for Spectrum Approximation [40.43008834125277]
  We show that there are distributions on $[-1,1]$ that cannot be approximated to accuracy $epsilon$ in Wasserstein-1 distance. No algorithm can compute an $epsilon$-accurate approximation to the spectrum of a normalized graph adjacency matrix with constant probability.
  arXiv  Detail & Related papers  (2023-07-02T05:03:38Z)
• Evaluation of a $^{88}$Sr$^+$ optical clock with a direct measurement of the blackbody radiation shift and determination of the clock frequency [0.0]
  We measure the clock output frequency against an independent $171$Yb$+$ ion clock. We find the absolute frequency of the $88$Sr$+$ clock transition to be $444779044095485.271(59),textHz$.
  arXiv  Detail & Related papers  (2022-12-16T19:30:03Z)
• On parametric resonance in the laser action [91.3755431537592]
  We consider the selfconsistent semiclassical Maxwell--Schr"odinger system for the solid state laser. We introduce the corresponding Poincar'e map $P$ and consider the differential $DP(Y0)$ at suitable stationary state $Y0$.
  arXiv  Detail & Related papers  (2022-08-22T09:43:57Z)
• Sharper Convergence Guarantees for Asynchronous SGD for Distributed and Federated Learning [77.22019100456595]
  We show a training algorithm for distributed computation workers with varying communication frequency. In this work, we obtain a tighter convergence rate of $mathcalO!!!(sigma2-2_avg!! . We also show that the heterogeneity term in rate is affected by the average delay within each worker.
  arXiv  Detail & Related papers  (2022-06-16T17:10:57Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.