Atomic Clock with<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>18</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>Room-Temperature Blackbody Stark Uncertainty

Beloy, K.; Hinkley, N.; Phillips, Nathaniel B.; Sherman, Jeffrey A.; Schioppo, M.; Lehman, John H.; Feldman, Albert; Hanssen, Leonard M.; Oates, C. W.; Ludlow, Andrew D.

doi:10.1103/physrevlett.113.260801

Cited by 125 publications

(106 citation statements)

References 30 publications

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“…These are used for state-of-the art optical clock experiments, and some of them are discussed as new SI frequency standards. Our result adds to existing work [41,42,43] validating computational methods used to predict the BBR shift in optical clocks.In summary, we demonstrate a novel method for the measurement of dipole matrix elements, which works despite the presence of additional decay channels. We attain an uncertainty on the 10 −3 level.…”

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confidence: 53%

Measurement of Dipole Matrix Elements with a Single Trapped Ion

et al. 2015

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We demonstrate a method to determine dipole matrix elements by comparing measurements of dispersive and absorptive light ion interactions. We measure the matrix element pertaining to the Ca II H line, i.e. the 4 2 S 1/2 ↔ 4 2 P 1/2 transition of 40 Ca + , for which we find the value 2.8928(43) ea0.Moreover, the method allows us to deduce the lifetime of the 4 2 P 1/2 state to be 6.904(26) ns, which is in agreement with predictions from recent theoretical calculations and resolves a longstanding discrepancy between calculated values and experimental results.PACS numbers: 37.10. Ty, 32.80.Qk, 03.67.Lx Methods for trapping and cooling single or few atoms, molecules or ions and manipulating them at the quantum level have opened up new avenues for precision laser spectroscopy. In particular, quantum logic techniques [1] have enabled a new accuracy regime of timekeeping with optical atomic clocks [2]. In contrast to atomic transition frequencies, dipole matrix elements and radiative lifetimes are still notoriously hard to determine at high accuracy, but are important for the quantification of black body radiation shifts of atomic clocks [3], interpretation of astrophysical spectra [4,5], novel approaches for the search for physics beyond standard model [6,7] and for testing the accuracy of atomic structure calculations [8].Regarding measurements of radiative lifetimes and transition matrix elements, established methods e.g. based on ion beams have been successfully complemented by novel techniques based on trapped particles. For 87 Rb, dipole matrix elements have been determined on the 10 −3 uncertainty level by diffraction in a condensate [9], while for the 6p 2 P o 1/2 state of 174 Yb + , the radiative lifetime has been measured by time-resolved counting of photons emitted from a single trapped ion [10]. A related technique was used for neutral 171 Yb in an optical lattice [11].The species Ca + is widely used in quantum optics experiments, and its II H line led to the discovery of the interstellar medium [12]. For 40 Ca + , branching ratios between different decay channels have been determined at uncertainties approaching the 10 −5 level [13,14], and lifetimes of metastable states have been accurately measured [15]. The radiative lifetime of the 4 2 P 1/2 excited state of 40 In this work, we determine the radiative decay rates and the lifetime of the 4 2 P 1/2 excited state of 40 Ca + together with the dipole matrix element of the 4 2 S 1/2 ↔ 4 2 P 1/2 transition. The cornerstone of our scheme is the comparison between the dispersive and absorptive interactions, which occur upon driving this transition with an off-resonant laser, see Fig. 1. As the method is based on the discrete discrimination of atomic states of a single trapped particle [17,18], it is robust against many systematic error sources which affect other existing methods.The off-resonant laser is characterized by its detuning ∆ from the 4 2 S 1/2 ↔ 4 2 P 1/2 transition, the Rabi frequency Ω and the relative amplitudes q , which characarXiv:1505.025...

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confidence: 53%

Measurement of Dipole Matrix Elements with a Single Trapped Ion

et al. 2015

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“…Our approach is based on adaptation of the synthetic frequency concept [V. I. Yudin At the present time, huge progress occurs for highprecision optical atomic clocks based on both neutral atoms in optical lattices [1][2][3][4][5][6][7][8] and trapped ions [9][10][11][12]. Exceptional accuracy and stability at the 10 −17 -10…”

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confidence: 99%

Synthetic frequency protocol for Ramsey spectroscopy of clock transitions

et al. 2016

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We develop an universal method to significantly suppress probe-induced shifts in any types of atomic clocks using the Ramsey spectroscopy. Our approach is based on adaptation of the synthetic frequency concept [V. I. Yudin, et al., Phys. Rev. Lett. 107, 030801 (2011) At the present time, huge progress occurs for highprecision optical atomic clocks based on both neutral atoms in optical lattices [1][2][3][4][5][6][7][8] and trapped ions [9][10][11][12]. Exceptional accuracy and stability at the 10 −17 -10level are achieved. Potential possibilities to achieve the level of 10 −19 become clearer for nuclear clocks [13-16] and for highly charged ions [17][18][19]. Great fundamental (e.g., in tests of fundamental physical theories such as QED, QCD, unification theories, cosmology, dark matter searches, etc.) and practical (navigation and information systems, gravity-geopotential surveying) importance of the current and long-range researches is wellknown and unquestionable. Current state, concomitant problems, and future prospects are well presented in the review [20].On the way to these remarkable achievements, different barriers arise, which require the development of new unconventional approaches. As an example, for some of the promising clock systems, one of the key problems is the frequency shift of the clock transition due to the excitation pulses themselves. For the case of magnetically induced spectroscopy [21,22] these shifts (quadratic Zeeman and ac-Stark shifts) could ultimately limit the achievable performance. Moreover, for ultranarrow transitions (e.g., electric octupole [23] and twophoton transitions [24,25]) the ac-Stark shift can be so large in some cases to rule out high accuracy clock performance at all. A similar limitation exists for clocks based on direct frequency comb spectroscopy [26,27] due to ac-Stark shifts induced by large numbers of off-resonant * Electronic address: viyudin@mail.ru laser modes.Unconventional solution to this important problem was proposed in the paper [28], in which so-called hyperRamsey method has been developed. Soon this approach was successfully realized in [29], where the huge suppression (by four orders of magnitude) of probe-induced shifts was experimentally demonstrated (see also [9]). However, a potential of this method was not going to be settled. In the experimental-theoretical paper [30] a 'stunning' result was recently shown: certain simple modification allows, in principle, totally(!) to exclude probeinduced shifts. Other hyper-Ramsey modification, having the same efficiency, was very soon proposed in the theoretical paper [31]. Because these phenomenal results can have far-reaching consequences for development of atomic clocks, it requires utterly thorough investigation of the schemes [30,31]. Besides, undoubted importance has a search of new variants to suppress probe-induced shifts with the near extremal efficiency.In this paper, we develop an universal method to dramatically suppress probe-induced shifts and their fluctuations in any type of atomic clock...

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“…A series of cutoff waveguides, possibly including detuned microwave cavities [28], can be used. More precise measurements of blackbody coefficients and temperature measurements, as in recent lattice clocks [14,29], may be useful in the future. Finally, juggling atoms [30] significantly improves the short-term stability [31], but this technique requires more effort than the methods above.…”

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confidence: 99%

Systematic Effects in Atomic Fountain Clocks

Gibble

2016

J. Phys.: Conf. Ser.

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Abstract. We describe recent advances in the accuracies of atomic fountain clocks. New rigorous treatments of the previously large systematic uncertainties, distributed cavity phase, microwave lensing, and background gas collisions, enabled these advances. We also discuss background gas collisions of optical lattice and ion clocks and derive the smooth transition of the microwave lensing frequency shift to photon recoil shifts for large atomic wave packets.

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Atomic Clock with1×10−18Room-Temperature Blackbody Stark Uncertainty

Cited by 125 publications

References 30 publications

Measurement of Dipole Matrix Elements with a Single Trapped Ion

Measurement of Dipole Matrix Elements with a Single Trapped Ion

Synthetic frequency protocol for Ramsey spectroscopy of clock transitions

Systematic Effects in Atomic Fountain Clocks

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