New Limits on the Drift of Fundamental Constants from Laboratory Measurements

Fischer, Marc; Kolachevsky, Nikolai N.; Zimmermann, M.; Holzwarth, Ronald; Udem, Thomas; Hänsch, Theodor W.; Abgrall, M.; Grünert, Jan; Maksimovic, I.; Bize, S.; Marion, H.; Santos, F. Pereira Dos; Lemonde, P.; Santarelli, G.; Laurent, Ph.; Clairon, A.; Salomon, Christophe; Haas, Martín; Jentschura, Ulrich D.; Keitel, Christoph H.

doi:10.1103/physrevlett.92.230802

Cited by 408 publications

(222 citation statements)

References 12 publications

Supporting

Mentioning

218

Contrasting

Unclassified

Order By: Relevance

“…The transportable fountain FOM has similarly been used as a primary standard in the measurement of the frequency ν H of the hydrogen 1S-2S transition performed at Max-Planck Institut in Garching (Germany) [30,47]. Two measurements performed over a 4 year period constrain fractional variations of ν Cs /ν H at the level of (3.…”

Section: Einstein Equivalence Principle and Stability Of Fundamental mentioning

confidence: 99%

“…[33,49]), it is possible to independently set limits on variations of α, g Rb /g Cs and g Cs (m e /m p ). These measurements test the stability of the electroweak interaction (α) and of the strong interaction (g Rb /g Cs , g Cs (m e /m p )) separately [47,49] and independently of any cosmological model.…”

Section: Einstein Equivalence Principle and Stability Of Fundamental mentioning

confidence: 99%

“…The second one (FOM), a transportable fountain, is derived from the PHARAO space clock prototype [9]. This fountain was transported on two occasions to the Max Planck Institute in Garching for direct frequency measurement of the hydrogen 1s → 2s transition [47](See section on stability of fundamental constants). The third one (FO2), a dual fountain operating with 133 Cs or 87 Rb, is described in [7].…”

Section: Recent Advances In Cesium and Rubidium Fountainsmentioning

confidence: 99%

See 2 more Smart Citations

Cold atom clocks and applications

Bize

Laurent

Abgrall

et al. 2005

J. Phys. B: At. Mol. Opt. Phys.

226

161

View full text Add to dashboard Cite

This paper describes advances in microwave frequency standards using laser-cooled atoms at BNM-SYRTE. First, recent improvements of the 133 Cs and 87 Rb atomic fountains are described. Thanks to the routine use of a cryogenic sapphire oscillator as an ultra-stable local frequency reference, a fountain frequency instability of 1.6 × 10 −14 τ −1/2 where τ is the measurement time in seconds is measured. The second advance is a powerful method to control the frequency shift due to cold collisions. These two advances lead to a frequency stability of 2 × 10 −16 at 50 000 s for the first time for primary standards. In addition, these clocks realize the SI second with an accuracy of 7 × 10 −16 , one order of magnitude below that of uncooled devices. In a second part, we describe tests of possible variations of fundamental constants using 87 Rb and 133 Cs fountains. Finally we give an update on the cold atom space clock PHARAO developed in collaboration with CNES. This clock is one of the main instruments of the ACES/ESA mission which is scheduled to fly on board the International Space Station in 2008, enabling a new generation of relativity tests.

show abstract

Section: Einstein Equivalence Principle and Stability Of Fundamental mentioning

confidence: 99%

Section: Einstein Equivalence Principle and Stability Of Fundamental mentioning

confidence: 99%

Section: Recent Advances In Cesium and Rubidium Fountainsmentioning

confidence: 99%

See 1 more Smart Citation

Cold atom clocks and applications

Bize

Laurent

Abgrall

et al. 2005

J. Phys. B: At. Mol. Opt. Phys.

226

161

View full text Add to dashboard Cite

show abstract

“…Measurements of a suspected temporal variation of the fine structure constant by means of atomic transitions have reached an limit for δα/α of less than 10 −16 yr −1 [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Nuclear structure of lowestTh229states and time-dependent fundamental constants

et al. 2009

View full text Add to dashboard Cite

The electromagnetic transition between the almost degenerate 5/2 + and 3/2 + states in 229 Th is deemed to be very sensitive to potential changes in the fine structure constant α. State of the art Hartree-Fock and Hartree-Fock-Bogoliubov calculations are performed to compute the difference in Coulomb energies of the two states which determines the amplification of variations in α into variations of the transition frequency. The kinetic energies are also calculated which reflect a possible variation in the nucleon or quark masses. A generalized Hellmann-Feynman theorem is proved including the use of density-matrix functionals. As the two states differ mainly in the orbit occupied by the last unpaired neutron the Coulomb energy difference results from a change in the nuclear polarization of the proton distribution. This effect turns out to be rather small and to depend on the nuclear model, the amplification varies between about −4 × 10 4 and +4 × 10 4 . Therefore much more effort must be put into the improvement of the nuclear models before one can draw conclusions from a measured drift in the transition frequency on a temporal drift of fundamental constants. All calculations published so far do not reach the necessary fidelity.

show abstract

“…This includes the above Rb/Cs result (see sect. 4), optical frequency measurements of H(1S-2S) [45], Yb + [46], Hg + [47], Dy [48] and Sr (see above, and [23] and references therein) against Cs, and the optical-to-optical ion clock frequency ratio Al + /Hg + [49]. The fit yields independent constraints for the three constants given in the first row of the Table in fig.…”

Section: Fundamental Physics Testsmentioning

confidence: 99%

Atomic fountains and optical clocks at SYRTE: Status and perspectives

Abgrall

Chupin

Sarlo

et al. 2015

Comptes Rendus. Physique

View full text Add to dashboard Cite

In this article, we report on the work done with the LNE-SYRTE atomic clock ensemble during the last 10 years. We cover progress made in atomic fountains and in their application to timekeeping. We also cover the development of optical lattice clocks based on strontium and on mercury. We report on tests of fundamental physical laws made with these highly accurate atomic clocks. We also report on work relevant to a future possible redefinition of the SI second. IntroductionResearch on highly accurate atomic frequency standards and their applications is making fast and steady progress. The quest for ever increased accuracy is advancing hand in hand with advances in quantum physics, with better understanding and manipulation of atomic systems, with exploration of fundamental laws of nature and with the development of important services and infrastructures for science and society. The quest for increased accuracy is also a powerful incentive to innovation in such areas as lasers, laser stabilization, low noise electronics, stable oscillators, low noise detection of optical signals, fiber devices and cold-atom based instrumentation for ground or space applications. Finally, in addition to enhancing existing applications, improved accuracy leads to new applications.This article focuses on key achievements and trends of the last 10 years. Over this period of time, the first generation of laser-cooled standards, using the atomic fountain geometry, reached maturity and had large impact on international timekeeping. The typical accuracy of these frequency standards, 2 parts in 10 16 , is now permanently accessible both locally and globally. At the same time, a new generation of optical clocks showed tremendous and steady improvement, gaining more than two orders of magnitude in a decade. To date, an accuracy of 6.4 × 10 −18 [1] was reported. Similarly, major improvements occurred in many other aspects of optical frequency metrology, notably in optical frequency combs and optical fiber links.In this article, we will report on developments of the LNE-SYRTE atomic clock ensemble since our 2004 report in the Special Issue of the Comptes Rendus de l'Académie des sciences on Fundamental Metrology [2]. This work exemplifies many of the above mentioned features of research on highly accurate atomic frequency standards. We will focus on frequency standards and their impact on timescales and timekeeping, on clock comparisons, including optical-to-microwave comparisons with combs, and their applications. Several

show abstract

New Limits on the Drift of Fundamental Constants from Laboratory Measurements

Cited by 408 publications

References 12 publications

Cold atom clocks and applications

Cold atom clocks and applications

Nuclear structure of lowestTh229states and time-dependent fundamental constants

Atomic fountains and optical clocks at SYRTE: Status and perspectives

Contact Info

Product

Resources

About