Frequency pulling by hyperfine σ transitions in cesium beam atomic frequency standards

Cutler, L.S.; Flory, Curt A.; Giffard, R. P.; Marchi, Andrea De

doi:10.1063/1.348637

Cited by 52 publications

(74 citation statements)

References 2 publications

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“…With some estimations regarding the transverse component of the microwave field and coupling of the atom to this field, using again [60] we infer an upper limit of the Ramsey pulling shift less than 10 −19 . We note here the favorable properties of Rb when comparing to Cs.…”

Section: G Rabi and Ramsey Pulling Shiftsmentioning

confidence: 77%

Contributing to TAI with a secondary representation of the SI second

et al. 2014

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Abstract-We report the first contribution to the international atomic time (TAI) based on a secondary representation of the SI second. This work is done with the LNE-SYRTE FO2-Rb fountain frequency standard using the 87 Rb ground state hyperfine transition. We describe FO2-Rb and how it is connected to local and international time scales. We report on local measurements of this frequency standard in the SI system, i.e. against primary frequency standards, down to a fractional uncertainty of 4.4 × 10 −16 , and on the establishment of the recommended value for the 87 Rb hyperfine transition by the CIPM. We also report on the process that led to the participation of the FO2-Rb frequency standard to Circular T and to the elaboration of TAI. This participation enables us to demonstrate absolute frequency measurement directly in terms of the SI second realized by the TAI ensemble with a statistical uncertainty of 1.1 × 10 −16 , therefore at the limit allowed by the accuracy of primary frequency standards. This work constitutes a demonstration of how other secondary representations, based on optical transitions, could also be used for TAI, and an investigation of a number of issues relevant to a future redefinition of the SI second.

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Section: G Rabi and Ramsey Pulling Shiftsmentioning

confidence: 77%

Contributing to TAI with a secondary representation of the SI second

et al. 2014

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“…The shift is qualitatively different from the Rabi-pulling shift, which is due to the microwave field driving neighboring m F = 0 (or π ) transitions between magnetically sensitive states without coupling to a clock state [13]. Work on Ramsey pulling has been published only for thermal beam clocks [12,14,15]. So far its contribution to the uncertainty budget of fountain clocks has been evaluated based on the theory specifically developed for thermal beam clocks by Cutler et al [12] and is generally estimated to be below 10 −16 when atomic state selection is employed.…”

Section: Introductionmentioning

confidence: 98%

“…Ramsey-pulling frequency shifts appear when the microwave field driving the clock transition couples magnetically sensitive states to the clock states via m F = ±1 (or σ ) transitions, which change the projection quantum number m F of the atom's total angular momentum F [12]. The shift is qualitatively different from the Rabi-pulling shift, which is due to the microwave field driving neighboring m F = 0 (or π ) transitions between magnetically sensitive states without coupling to a clock state [13].…”

Section: Introductionmentioning

confidence: 99%

Initial atomic coherences and Ramsey frequency pulling in fountain clocks

2014

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In the uncertainty budget of primary atomic cesium fountain clocks, evaluations of frequency-pulling shifts of the hyperfine clock transition caused by unintentional excitation of its nearby transitions (Rabi and Ramsey pulling) have been based so far on an approach developed for cesium beam clocks. We re-evaluate this type of frequency pulling in fountain clocks and pay particular attention to the effect of initial coherent atomic states. We find significantly enhanced frequency shifts caused by Ramsey pulling due to sublevel population imbalance and corresponding coherences within the state-selected hyperfine component of the initial atom ground state. Such shifts are experimentally investigated in an atomic fountain clock and quantitative agreement with the predictions of the model is demonstrated.

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“…Therefore the pi transitions can be treated to very good approximation as completely independent. A detailed theoretical analysis was performed [2] and this suspicion was confirmed. The analysis will not be described in detail here but some of the results will be presented as well as some experimental verification of the theory.…”

Section: Introductionmentioning

confidence: 86%

“…The pulling behavior in these tubes is quite different from the usual Rabi pulling which is caused by the residual background slope due to incomplete cancellation of the skirts of the neighboring AM=O (pi) transitions. (In this paper and in reference [2] we have used pi and sigma to designate parallel and perpendicular, respectively, orientation of the microwave magnetic field with respect to the Cfield. This is in contrast to the usual optical definition in which pi and sigma mean that the optical electric field is parallel and perpendicular, respectively, to the static magnetic field.)…”

Section: Introductionmentioning

confidence: 99%

Frequency pulling in cesium beam frequency standards due to delta M=+or-1 (sigma) transitions

Cutler

Flory

Giffard

et al.

Proceedings of the 45th Annual Symposium on Frequency Control 1991

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Measurements have shown that cesium tubes with appreciable ~M = k l (sigma) transitions have significant frequency departures from the Breit-Rabi value as a function of Cfield. The behavior is quite different from the usual pulling by AM=O (pi) transitions (Rabi pulling). A detailed theoretical analysis of the pulling by both sigma and pi transitions using a six level model has been carried out and some of the results are presented here. The most important result is that the contributions to the clock transition probability from the closest sigma transitions have the Ramsey shape but with a shifted center when the state populations are asymmetric. Thus the pulling by these sigma transitions, which we call Ramsey pulling, cannot be reduced by third harmonic detection or other background slope removal techniques that are effective in Rabi pulling. Ramsey pulling can only be reduced by decreasing the sigma transitions and the population asymmetries. Optical pumping could be arranged that would have clear advantage with regard to population asymmetries.

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Frequency pulling by hyperfine σ transitions in cesium beam atomic frequency standards

Cited by 52 publications

References 2 publications

Contributing to TAI with a secondary representation of the SI second

Contributing to TAI with a secondary representation of the SI second

Initial atomic coherences and Ramsey frequency pulling in fountain clocks

Frequency pulling in cesium beam frequency standards due to delta M=+or-1 (sigma) transitions

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