Absolute frequency measurement of an Yb optical clock at the 10⁻¹⁶ level using International Atomic Time

Abstract

We report on the absolute frequency measurement of the 6s 2 1 S 0 -6s6p 3 P 0 transition in 171 Yb with a fractional uncertainty of 7.3 × 10 -16 . A global positioning system carrier phase frequency transfer was established between National Institute of Metrology of China and East China Normal University, which linked the optical frequency of the ECNU Yb1 clock to the second in the International System of Units (SI) through international atomic time. Frequency measurements were carried out in 15 separate days with a total time over 3.8 × 10 5 s. The absolute frequency was determined to be 518 295 836 590 863.30(38) Hz. Our result is in good agreement with the recommended value in neutral Yb as a secondary representation of the SI second endorsed by the International Committee for Weights and Measures.

Absolute frequency measurement of a Yb optical clock at the limit of the Cs fountain

“…We also show the updated uncertainty budget of IT-Yb1 that has a relative uncertainty of 1.9 × 10 −17 . In figure 4 our measurement reported as a red square is compared to the recommended secondary representations of the second and previous absolute frequency measurements [14,[19][20][21][22][23][24][25][26][27][28][29]54], showing a good agreement. Moreover, we note that this measurement supersedes the local frequency measurement we reported in [19], as it extends the analyzed data period.…”

“…One of the secondary representations of the second recommended by the CCTF is the transition 1 S 0 → 3 P 0 of 171 Yb. Absolute frequency measurements of this clock transition have been realized by several metrological institutes worldwide [14,[19][20][21][22][23][24][25][26][27]. At INRiM we measured the absolute frequency of the 171 Yb clock (IT-Yb1) relative to our local cryogenic Cs fountain (IT-CsF2) [28] and via International Atomic Time (TAI) [29].…”

Improved absolute frequency measurement of the strontium ion clock using a GPS link to the SI second

“…Using the intensity shift coefficient of κ(1092 nm) = −1.6( 4) mHz (W m −2 ) −1 [43], and a beam waist of w 0 = 51(2) µm [17], the shift is estimated to be −72 (31) µHz, or −0.16(7) × 10 −18 in fractional frequency units.…”

“…In this paper, we report on an improved absolute frequency measurement of the reference transition of the National Research Council Canada (NRC) 88 Sr + ion clock [17][18][19] relative to the SI second through a Global Positioning System (GPS) link. A significant number of absolute frequency measurements of optical standards relative to the SI second through International Atomic Time (TAI) via GPS links have been performed recently [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. In our data analysis, the frequency drift of a flywheel oscillator, an active hydrogen maser, with respect to the SI second was first evaluated for a period of 190 days for accurate determination of the frequency offset between the 88 Sr + ion clock and the maser.…”

Free-bound excitation and predissociation of ytterbium dimers near theS01−P11atomic transition

“…Ytterbium is a lanthanide element with an electronic configuration similar to those of alkaline-earth atoms. Ultracold Yb atoms have been utilized for various applications such as quantum simulations [1,2] and atomic clocks [3][4][5][6]. One of the remarkable features of alkaline-earth(-like) atoms is the existence of metastable ( 3 P0, 3 P2) states of long radiative lifetimes on the order of seconds or more.…”