TY - JOUR

T1 - Evaluation of a Sr+ 88 Optical Clock with a Direct Measurement of the Blackbody Radiation Shift and Determination of the Clock Frequency

AU - Steinel, M.

AU - Shao, H.

AU - Filzinger, M.

AU - Lipphardt, B.

AU - Brinkmann, M.

AU - Didier, A.

AU - Mehlstäubler, T. E.

AU - Lindvall, T.

AU - Peik, E.

AU - Huntemann, N.

N1 - Funding Information: We acknowledge support by the Projects No. 20FUN01 TSCAC and No. 17FUN07 CC4C, which have received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme, and by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under SFB 1227 DQ-mat—Project-ID No. 274200144—within Project B02. This work was partially supported by the Max Planck–RIKEN–PTB Center for Time, Constants and Fundamental Symmetries.

PY - 2023/8/23

Y1 - 2023/8/23

N2 - We report on an evaluation of an optical clock that uses the S21/2→D25/2 transition of a single Sr+88 ion as the reference. In contrast to previous work, we estimate the effective temperature of the blackbody radiation that shifts the reference transition directly during operation from the corresponding frequency shift and the well-characterized sensitivity to thermal radiation. We measure the clock output frequency against an independent Yb+171 ion clock, based on the S21/2(F=0)→F27/2(F=3) electric octupole (E3) transition, and determine the frequency ratio with a total fractional uncertainty of 2.3×10-17. Relying on a previous measurement of the Yb+171 (E3) clock frequency, we find the absolute frequency of the Sr+88 clock transition to be 444 779 044 095 485.277(59) Hz. Our result reduces the uncertainty by a factor of 3 compared with the previously most accurate measurement and may help to resolve so far inconsistent determinations of this value. We also show that for three simultaneously interrogated Sr+88 ions, the increased number causes the expected improvement of the short-term frequency instability of the optical clock without degrading its systematic uncertainty.

AB - We report on an evaluation of an optical clock that uses the S21/2→D25/2 transition of a single Sr+88 ion as the reference. In contrast to previous work, we estimate the effective temperature of the blackbody radiation that shifts the reference transition directly during operation from the corresponding frequency shift and the well-characterized sensitivity to thermal radiation. We measure the clock output frequency against an independent Yb+171 ion clock, based on the S21/2(F=0)→F27/2(F=3) electric octupole (E3) transition, and determine the frequency ratio with a total fractional uncertainty of 2.3×10-17. Relying on a previous measurement of the Yb+171 (E3) clock frequency, we find the absolute frequency of the Sr+88 clock transition to be 444 779 044 095 485.277(59) Hz. Our result reduces the uncertainty by a factor of 3 compared with the previously most accurate measurement and may help to resolve so far inconsistent determinations of this value. We also show that for three simultaneously interrogated Sr+88 ions, the increased number causes the expected improvement of the short-term frequency instability of the optical clock without degrading its systematic uncertainty.

KW - physics.atom-ph

KW - quant-ph

UR - http://www.scopus.com/inward/record.url?scp=85169292887&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2212.08687

DO - 10.48550/arXiv.2212.08687

M3 - Article

VL - 131

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 8

M1 - 083002

ER -