# ^{27}Al^{+} Quantum-Logic Clock with a Systematic Uncertainty below 10^{-18}.

@article{Brewer201927AlQC,
title={^\{27\}Al^\{+\} Quantum-Logic Clock with a Systematic Uncertainty below 10^\{-18\}.},
author={Samuel M. Brewer and J.-S. Chen and Aaron Hankin and Ethan R. Clements and Chin-wen Chou and David J. Wineland and David B. Hume and David R. Leibrandt},
journal={Physical review letters},
year={2019},
volume={123 3},
pages={
033201
}
}
• Published 20 February 2019
• Physics
• Physical review letters
We describe an optical atomic clock based on quantum-logic spectroscopy of the ^{1}S_{0}↔^{3}P_{0} transition in ^{27}Al^{+} with a systematic uncertainty of 9.4×10^{-19} and a frequency stability of 1.2×10^{-15}/sqrt[τ]. A ^{25}Mg^{+} ion is simultaneously trapped with the ^{27}Al^{+} ion and used for sympathetic cooling and state readout. Improvements in a new trap have led to reduced secular motion heating, compared to previous ^{27}Al^{+} clocks, enabling clock operation with ion secular…
242 Citations

## Figures and Tables from this paper

Investigation of experimental issues concerning successful operation of quantum-logic-based $$^{27}\hbox {Al}^+$$ ion optical clock
Successful operations of quantum-logic-based $$^{27}\hbox {Al}^+$$ ion optical clocks have been reported by several groups. But there are still several lingering issues. The first is the proper
Fock-space relativistic coupled-cluster calculation of a hyperfine-induced 1S0→3P0o clock transition in Al+
• Physics
• 2021
We have developed an all-particle Fock-space relativistic coupled-cluster method to calculate the properties of two-valence atoms and ions. Using the method we compute the properties associated with
Narrow-line Cooling and Determination of the Magic Wavelength of Cd.
• Physics
Physical review letters
• 2019
The magic wavelength of the (5s^{2})^{1}S_{0}-^{3}P_{1} clock transition of ^{111}Cd to be 419.88(14) and 420.1(7) nm is experimentally and theoretically determined.
Systematic uncertainty due to background-gas collisions in trapped-ion optical clocks
• Physics
Physical Review A
• 2019
We describe a framework for calculating the frequency shift and uncertainty of trapped-ion optical atomic clocks caused by background-gas collisions, and apply this framework to an $^{27}$Al$^+$
Quadruply Ionized Barium as a Candidate for a High-Accuracy Optical Clock.
• Physics
Physical review letters
• 2020
The differential static scalar polarizability is found to be small and negative, providing suppressed sensitivity to blackbody radiation while simultaneously allowing cancellation of Stark and excess micromotion shifts.
Coherent control of $$^{171}\mathrm{Yb}^{+}$$ ion qubit states and thermometry using motional decoherence
• Physics
• 2021
$$^{171} \mathrm{Yb}^{+}$$ ions were trapped in a quadrupole ion trap. A mode-locked pulse laser at 355 nm was used to generate a frequency comb to drive a Raman transition between the ground
Detection of the 5p – 4f orbital crossing and its optical clock transition in Pr9+
• Materials Science
Nature Communications
• 2019
The authors demonstrate a configuration crossing in the highly charged ion praseodymium (Pr9+) and determine the frequency of a potential reference transition for ahighly charged ion clock.
Sympathetic cooling of a large ${}^{113}\mathrm{{Cd}}^{+}$ ion crystal with ${}^{40}\mathrm{{Ca}}^{+}$ in a linear Paul trap
• Materials Science
• 2022
S. N. Miao,1, ∗ H. R. Qin,1, 2, ∗ N. C. Xin,1 Y. T. Chen,1 J. W. Zhang,1, † and L. J. Wang1, 2, ‡ 1State Key Laboratory of Precision Measurement Technology and Instruments, Key Laboratory of Photon
Geopotential measurement with a robust, transportable Ca+ optical clock
• Physics
• 2020
We present a robust, transportable ${\mathrm{Ca}}^{+}$ optical clock, with a systematic uncertainty of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ limited by the black-body
Polarizability assessments of ion-based optical clocks
• Physics
Physical Review A
• 2019
It is shown that the dynamic differential scalar polarisability of the $S_{1/2}-D_{5/2}$ transition in $^{138}$Ba$^+$ can be determined to an inaccuracy below $0.5\%$ across a wide wavelength range

## References

SHOWING 1-10 OF 81 REFERENCES
Frequency comparison of two high-accuracy Al+ optical clocks.
• Physics
Physical review letters
• 2010
An optical clock with a fractional frequency inaccuracy of 8.6x10{-18}, based on quantum logic spectroscopy of an Al+ ion, is constructed, consistent with the accuracy limit of the older clock.
Hyperfine-mediated electric quadrupole shifts in Al+ and In+ ion clocks | NIST
• Physics
• 2017
We evaluate the electric quadrupole moments of the ${^1}\!S_0$ and ${^3}\!P_0$ clock states of $^{27}$Al$^+$ and $^{115}$In$^+$. To capture all dominant contributions, our analysis extends through
Precise determination of micromotion for trapped-ion optical clocks
• Physics
• 2015
As relative systematic frequency uncertainties in trapped-ion spectroscopy are approaching the low $10^{-18}$ range, motional frequency shifts account for a considerable fraction of the uncertainty
Multipolar theory of blackbody radiation shift of atomic energy levels and its implications for optical lattice clocks
• Physics
• 2006
Blackbody radiation (BBR) shifts of the {sup 3}P{sub 0}-{sup 1}S{sub 0} clock transition in the divalent atoms Mg, Ca, Sr, and Yb are evaluated. The dominant electric-dipole contributions are
Ultrastable optical clock with two cold-atom ensembles
• Physics
• 2017
Optical clocks with a record low zero-dead-time instability of 6 × 10–17 at 1 second are demonstrated in two cold-ytterbium systems. The two systems are interrogated by a shared optical local
Systematic evaluation of an atomic clock at 2 × 10−18 total uncertainty
• Physics
Nature communications
• 2015
This work performs a new accuracy evaluation of the JILA Sr clock, reducing many systematic uncertainties that limited previous measurements, such as those in the lattice ac Stark shift, the atoms' thermal environment and the atomic response to room-temperature blackbody radiation.
Frequency Ratio of Al+ and Hg+ Single-Ion Optical Clocks; Metrology at the 17th Decimal Place
• Physics
Science
• 2008
Repeated measurements during the past year yield a preliminary constraint on the temporal variation of the fine-structure constant α of α ofbatchmode, a regime of operation for atomic clocks based on optical transitions, promising even higher performance.
Resolved-sideband Raman cooling of a bound atom to the 3D zero-point energy.
• Monroe
• Physics
Physical review letters
• 1995
We report laser cooling of a single $^{9}\mathrm{Be}^{+}$ ion held in a rf (Paul) ion trap to where it occupies the quantum-mechanical ground state of motion. With the use of resolved-sideband
Quantum coherence between two atoms beyond Q=10(15).
• Physics
Physical review letters
• 2011
It is demonstrated a method to detect the individual quantum states of two Al(+) ions in a Mg(+)-Al(+-Al(+) linear ion chain without spatially resolving the ions.
Single-Ion Atomic Clock with 3×10(-18) Systematic Uncertainty.
• Physics
Physical review letters
• 2016
An optical frequency standard based on the E3 transition of a single trapped (171)Yb+ ion is experimentally investigated and a Ramsey-type excitation scheme that provides immunity to probe-induced frequency shifts is utilized.