Evaluation of the systematic shifts of a – optical clock

Kaifeng Cui; Sijia Chao; Chenglong Sun; Shaomao Wang; Ping Zhang; Yuanfei Wei; Jinbo Yuan; Jian Cao; Hualin Shu; Xueren Huang

doi:10.1140/epjd/s10053-022-00451-1

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2024 Impact factor 1.5

Atomic, Molecular, Optical and Plasma Physics

Eur. Phys. J. D (2022) 76: 140
https://doi.org/10.1140/epjd/s10053-022-00451-1

Regular Article – Cold Matter and Quantum Gases

Evaluation of the systematic shifts of a $^{40} {Ca}^{+}$ ${}^{40}\text {Ca}^{+}$ – $^{27} {Al}^{+}$ ${}^{27}\text {Al}^{+}$ optical clock

Kaifeng Cui¹^,2^a, Sijia Chao¹^,2, Chenglong Sun¹^,2^,3, Shaomao Wang¹^,2^,3, Ping Zhang¹^,2^,3, Yuanfei Wei¹^,2^,3, Jinbo Yuan¹^,2, Jian Cao¹^,2, Hualin Shu¹^,2 and Xueren Huang¹^,2^,4^k

¹ Key Laboratory of Atomic Frequency Standards, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, 430071, Wuhan, China
² State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, 430071, Wuhan, China
³ University of the Chinese Academy of Sciences, 100049, Beijing, China
⁴ Wuhan Institute of Quantum Technology, 430206, Wuhan, China

^a cuikaifeng@apm.ac.cn
^k hxueren@apm.ac.cn

Received: 21 April 2022
Accepted: 27 June 2022
Published online: 9 August 2022

Abstract

Quantum-logic-based $^{27} {Al}^{+}$ ${}^{27}\text {Al}^{+}$ optical clock has been demonstrated in several schemes as there are different choices of the auxiliary ion species. In this paper, we present the first detailed evaluation of the systematic shift and the total uncertainty of an $^{27} {Al}^{+}$ ${}^{27}\text {Al}^{+}$ optical clock sympathetically cooled by a $^{40} {Ca}^{+}$ ${}^{40}\text {Ca}^{+}$ ion. The total systematic uncertainty of the $^{40} {Ca}^{+} -^{27} {Al}^{+}$ ${}^{40}\text {Ca}^{+}- {}^{27}\text {Al}^{+}$ quantum logic clock has been estimated to be $7.9 \times 10^{- 18}$ $7.9\times 10^{-18}$ , which was mainly limited by the uncertainty of the quadratic Zeeman shift. By comparing the frequency of two counter-propagating clock beams on the same ion, we measured the frequency stability to be $3.7 \times 10^{- 14} / \sqrt{τ}$ $3.7 \times 10^{-14} /\sqrt{\tau }$ .