An 27Al+ quantum-logic clock with systematic uncertainty below 10-18

Published

July 15, 2019

Author(s)

Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, Ethan Clements, Chin-wen Chou, David J. Wineland, David Hume, David Leibrandt

Abstract

We describe an optical atomic clock based on quantum-logic spectroscopy of the ¹S₀ <- -> ³P₀ transition in ²⁷Al⁺ with a systematic uncertainty of 9.0 x 10-19 and a frequency stability of 1.2 X 10^-15/(T^1/2). A ²⁵Mg⁺ ion is simultaneously trapped with the ²⁷Al⁺ ion and used for sympathetic cooling and state readout during clock operation. Improvements in a new trap have led to reduced secular motion heating, compared to previous 27Al+ clocks, enabling clock operation with ion motion near the three-dimensional ground state. Operating the clock with a lower trap drive frequency has reduced excess micromotion, compared to previous ²⁷Al⁺ clocks, leading to a reduced time-dilation shift uncertainty. Other systematic uncertainties including those due to blackbody radiation and the second-order Zeeman effect have also been reduced.

Citation

Physical Review Letters

Pub Type

Journals

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Keywords

Atomic clocks, lattic clocks, optical clocks, Precision Measurements, Trapped ions

Citation

Brewer, S. , Chen, J. , Hankin, A. , Clements, E. , Chou, C. , Wineland, D. , Hume, D. and Leibrandt, D. (2019), An ²⁷Al+ quantum-logic clock with systematic uncertainty below 10^-18, Physical Review Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=927399 (Accessed October 16, 2025)