# Frequency comparison of two high-accuracy Al+ optical clocks.

@article{Chou2010FrequencyCO,
title={Frequency comparison of two high-accuracy Al+ optical clocks.},
author={Chin-wen Chou and David B. Hume and J. C. J. Koelemeij and David J. Wineland and Till Rosenband},
journal={Physical review letters},
year={2010},
volume={104 7},
pages={
070802
}
}
• Published 24 November 2009
• Physics
• Physical review letters
We have constructed an optical clock with a fractional frequency inaccuracy of 8.6x10{-18}, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser cool the Al+ ion and detect its quantum state. The frequency of the {1}S{0}<-->{3}P{0} clock transition is compared to that of a previously constructed Al+ optical clock with a statistical measurement uncertainty of 7.0x10{-18}. The two clocks exhibit a relative stability of 2.8x10{-15}tau…
749 Citations

## Figures and Tables from this paper

Systematic evaluation of a 171Yb optical clock by synchronous comparison between two lattice systems
• Physics
Scientific Reports
• 2018
S synchronous comparisons against a second 171Yb lattice system were implemented to accelerate the evaluation and paves the way to measuring the absolute clock transition frequency relative to the primary Cs standard or against the International System of Units second.
Trapped-ion optical atomic clocks at the quantum limits | NIST
• Physics
• 2017
Frequency and its inverse, time, are the most accurately measured quantities. Historically, improvements in the accuracy of clocks have enabled advances in navigation, communication, and science.
A compact, transportable single-ion optical clock with 7.8 × 10−17 systematic uncertainty
• Physics
• 2017
A transportable optical clock based on the 4s2S1/2-3d2D5/2 electric quadrupole transition at 729 nm of a single 40Ca+ ion trapped in a mini Paul trap has been developed. The physical system of the
Quantum projection noise limited stability of a 88Sr+ atomic clock
• Physics
• 2016
The evaluated accuracy of a single trapped 88Sr+ ion clock referenced to the 5s2 S1/2 - 4d 2 D5/2 transition at 445 THz at the National Research Council of Canada has reached 1.2 x 10-17 over recent
Compact Optical Atomic Clock Based on a Two-Photon Transition in Rubidium
• Physics
• 2018
Extra-laboratory atomic clocks are necessary for a wide array of applications (e.g. satellite-based navigation and communication). Building upon existing vapor cell and laser technologies, we
An optical lattice clock with accuracy and stability at the 10−18 level
• Physics
Nature
• 2014
This work demonstrates a many-atom system that achieves an accuracy of 6.4 × 10−18, which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude.
A transportable 40Ca+ single-ion clock with $7.7\times 10^{-17}$ systematic uncertainty
• Physics
• 2016
: A transportable optical clock refer to the 4s 2 S 1/2 -3d 2 D 5/2 electric quadrupole transition at 729 nm of single 40 Ca + trapped in mini Paul trap has been developed. The physical system of 40
Frequency comparison of optical lattice clocks
• Physics
Optical Engineering + Applications
• 2011
We demonstrate the frequency comparison of two optical lattice clocks at the relative stabilities close to the quantum projection noise (QPN) limit of optical lattice clocks. This stable frequency
Optical clock based on a sympathetically-cooled indium ion
• Physics
Hyperfine Interactions
• 2019
We report on the progress of an optical clock based on an indium ion (115In+) sympathetically cooled with a calcium ion (40Ca+) in a linear trap. In our previous work, we have measured the clock

## References

SHOWING 1-10 OF 68 REFERENCES
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.
Single-atom optical clock with high accuracy.
• Physics
Physical review letters
• 2006
A comparison between the cesium fountain standard NIST-F1, which has been evaluated with an inaccuracy of about 4 x 10 (-16), and an optical frequency standard based on an ultraviolet transition in a single, laser-cooled mercury ion for which the fractional systematic frequency uncertainty was below 7.2 x 10(-17).
The 31S0-33P0 transition in the aluminum isotope ion 26A1+: a potentially superior passive laser frequency standard and spectrum analyzer.
• Physics
Proceedings of the National Academy of Sciences of the United States of America
• 1992
The aluminum 26 isotope ion is proposed here as a possible candidate for a superior atomic clock because of the extraordinarily long lifetime of the 33P0 state and a potential clock transition (31S0-33P0) linewidth of 300 microHz.
High-fidelity adaptive qubit detection through repetitive quantum nondemolition measurements.
• Physics
Physical review letters
• 2007
This work implements qubit measurements based on the repetitive transfer of information and quantum nondemolition detection, which leads to exponentially lower error rates compared to using a fixed number of detection cycles.
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
Laser-cooling limits and single-ion spectroscopy.
• Physics
Physical review. A, General physics
• 1987
Sideband cooling of an ion in an rf (Paul) trap is reexamined including the effects of finite laser bandwidth and the energy of the rf micromotion and the implications for high-resolution, high-accuracy spectroscopy are investigated.
Monoion oscillator as potential ultimate laser frequency standard
• H. Dehmelt
• Physics
IEEE Transactions on Instrumentation and Measurement
• 1982
An individual atomic ion localized in the center of a small Paul RF quadrupole trap has potential as an ultimate laser frequency standard because the ion may be brought to `a state of complete rest
Minimization of ion micromotion in a Paul trap
• Physics
• 1998
Micromotion of ions in Paul traps has several adverse effects, including alterations of atomic transition line shapes, significant second-order Doppler shifts in high-accuracy studies, and limited
Sub-Hertz optical frequency comparisons between two trapped 171Yb+ ions.
• Physics
Physical review letters
• 2005
In the absence of external perturbations the authors find a mean frequency difference between the two trapped ions of 0.26(42) Hz, comparable to the agreement found in the most accurate comparisons between cesium fountain clocks.