Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

A High-Performance Optical Lattice Clock Based On Bosonic Atoms

S. Origlia, M.S. Pramod

Published Feb 24, 2018• 1 citation
Publisher

Abstract

Optical lattice clocks with uncertainty and instability in the 10􀀀17-range and below have so far been demonstrated exclusively using fermions. Here, we demonstrate a bosonic optical lattice clock with 3 10􀀀18 instability and 2:0 10􀀀17 accuracy, both values improving on previous work by a factor 30. This was enabled by probing the clock transition with an ultra-long interrogation time of 4 s, using the long coherence time provided by a cryogenic silicon resonator, by careful stabilization of relevant operating parameters, and by operating at low atom density. This work demonstrates that bosonic clocks, in combination with highly coherent interrogation lasers, are suitable for highaccuracy applications with particular requirements, such as high reliability, transportability, operation in space, or suitability for particular fundamental physics topics. As an example, we determine the 88Sr { 87Sr isotope shift with 12 mHz uncertainty.

DOI
10.5281/zenodo.1197052

Related papers

A high-performance bosonic optical lattice clock

Stefano Origlia

Optical clocks are being developed worldwide and are at the forefront of frequency metrology. Today they outperform microwave clocks instability and inaccuracy by two orders of magnitude, raising discussion about the redefinition of the SI second. Their outstanding performances are paving the way to applications in different fields apart from metrology. Optical clocks can be used for geodetic measurements, such as chronometric levelling, and fundamental physics experiments. These applications require transportable, and even space-born optical clocks that are in development. Space optical clocks will serve as a high accurate references for intercontinental clock comparisons, and will also provide a unique test bench for fundamental physics theories, such as Einstein’s prediction of time dilation and equivalence principle. This work presents the development and characterization of a transportable strontium optical lattice clock, realised in the framework of the ESA I-SOC (Space Optical Clock on the ISS) mission. The aim of the project is to investigate new technologies and techniques, in order to develop a robust apparatus as demonstrator for space applications. Special effort has been made to reduce the size and weight of the clock, so as to meet the stringent requirements of a space mission. The system reported here is one of the most compact optical clock to date, with a total volume of only 1 m3, excluding electronics. The clock is operated with the strontium bosonic isotope 88Sr: this is preferable to the fermionic counterpart 87Sr, commonly used in optical lattice clocks, if simplicity and reliability are required. However, in terms of accuracy, bosonic clocks present some disadvantages compared with the fermionic ones, which have significantly slowed down their development for metrological applications. We characterised the relevant operating parameters and their effect on the clock accuracy and instability. Exploiting a clock laser offering an outstanding stability, we were able to demonstrate a clock fractional instability of 3×10-18 , and an inaccuracy of 2×10-17: both values represent a factor of 30 improvement compared with previous works on bosonic optical clocks. These results suggest that, in the near future, bosonic clocks may become competitive to their fermionic counterparts. This is of interest for applications such as time scale realization, transportable clocks, or for test of fundamental physics. As an example, we measured the 88Sr-87Sr isotope shift, with an uncertainty of 12 mHz.

•Jan 1, 2018•1 citation

Towards an optical clock for space: Compact, high-performance optical lattice clock based on bosonic atoms

Stefano Origlia, Mysore Srinivas Pramod, Stephan Schiller +9 more

Optical clocks operated on satellites are expected to open up new opportunities in time transfer, geodesy, fundamental physics, and satellite navigation. Here we demonstrate an important first step towards this goal: a modular, compact, optical lattice clock (OLC) system that achieves $2.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ fractional uncertainty. The clock is operated with bosonic strontium and improves the performance of bosonic OLCs by a factor of 30. This has important implications for future use of bosonic OLCs in fundamental physics and metrology. We make use of the clock's metrological performance to measure, with independent clocks, the isotope shift of the $^{1}S_{0}\ensuremath{\rightarrow}^{3}P_{0}$ transitions of $^{88}\mathrm{Sr}$ and $^{87}\mathrm{Sr}$, with an uncertainty of 12 mHz. The ratio of the transition frequencies is thus determined with $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ fractional uncertainty.

arXiv:1803.03157•Physical Review A•Nov 29, 2018•142 citations

Optical lattice clocks toward 10-17uncertainty

Masao Takamoto, Tomoya Akatsuka, Hidekazu Hachisu +1 more

We discuss two possible configurations for optical lattice clocks; a one-dimensional (1D) lattice loaded with spinpolarized fermions, and a three-dimensional (3D) lattice loaded with bosons. In the former scheme, collisional frequency shifts are suppressed by the quantum statistical property of identical fermions. This Pauli blocking of collisions is critically dependent on the degree of spin polarization of the fermionic atoms, which we carefully investigated in the Rabi excitation process of the clock transition. In the latter scheme, a single occupancy lattice suppresses bunching of bosons and collisional frequency shifts. We demonstrate a frequency comparison of these two optical lattice clocks based on fermionic 87Sr and bosonic 88Sr. Operating these clocks parallely has yielded a stability approaching 10−17. Such measurements are an important step to ascertain the lattice clocks' uncertainty at the 10−17 level and beyond.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 20, 2009•0 citations

Optical Lattice Clock with Spin-1/2 Ytterbium Atoms

N. Lemke

An optical lattice clock probes a spectrally narrow electronic transition in an ensemble of optically trapped, laser-cooled atoms, for use as a time and frequency standard. To date, several lattice clocks have been demonstrated with superior stability and accuracy compared to primary frequency standards based on microwave transitions. Yet, the question of which atomic system (including the element and isotope) performs best as a lattice clock remains unsettled. This thesis describes the first detailed investigation of an optical lattice clock using a spin-1/2 isotope of the ytterbium atom. A spin-1/2 system possesses several advantages over higher-spin systems, including a simplified level structure (allowing for straightforward manipulation of the nuclear spin state) and the absence of any tensor light shift from the confining optical lattice. Moreover, the ytterbium atom (Yb) stands among the leading lattice clock candidates, offering a high-performance optical clock with some degree of experimental simplicity. The frequency stability of the Yb clock is highlighted by resolving an ultra-narrow clock spectrum with a full-width at half-maximum of 1 Hz, corresponding to a record quality factor Q = ν0/Δν = 5 × 1014. Moreover, this system can be highly accurate, which is demonstrated by characterizing the Yb clock frequency at the 3 × 10-16 level of fractional uncertainty, with further progress toward a ten-fold improvement also presented. To reach this low level of uncertainty required careful consideration of important systematic errors, including the identification of the Stark-canceling wavelength, where the clock’s sensitivity to the lattice intensity is minimized, a precise determination of the static polarizability of the clock transition, and the measurement and control of atom-atom collisions.

•Jan 1, 2012•7 citations

Developments to improve the stability of optical lattice clocks

S. Bize, Bess Fang, Yann Le Coq +5 more

Abstract We present several developments aimed at improving the stability of optical lattice clocks. First, we present our developments of an optical lattice clock using neutral mercury. We mention recent advances made with the fermionic isotope 199Hg. We also mention our work aimed at using bosonic isotopes, which offer the possibility to circumvent the relatively short lifetime of the upper clock state in 199Hg. Second, we present our work on a non-destructive detection in a Sr optical lattice clock. We describe developments that brought the detection scheme from the classical non-destructive regime to the quantum non-destructive regime. Our detection scheme is practical and has the capability to the used beyond proving the principle. Finally, we present our work on laser stabilization using spectral hole burning in a Eu3+:Y2SiO5 crystal at cryogenic temperatures. We describe our development of low noise interrogation based on digital IQ modulation and detection that can probe multiple spectral features simultaneously, as well as several investigations towards fluctuating environmental factors. These advances, individually or combined for example with spectral purity transfer with combs and composite clock approaches, shall bring significant progress in clock stability and accuracy.

Journal of Physics Conference Series•Nov 1, 2024•1 citation

Frequency comparison of optical lattice clocks

Masao Takamoto, T. Takano, Hidetoshi Katori

We demonstrate the frequency comparison of two optical lattice clocks at the relative stabilities close to the quantum projection noise (QPN) limit of optical lattice clocks. This stable frequency comparison is accomplished by synchronous interrogations of two clocks by a common probe laser, which allows us to cancel out the probe laser's frequency noise. We perform the frequency comparison of a one-dimensional (1D) optical lattice clock with spin-polarized fermions 87Sr and a three-dimensional (3D) optical lattice clock with unity-occupation bosons 88Sr and achieve the Allan standard deviation of σγ(τ)=4×10-16 τ-1/2, which corresponds to the QPN limited stability for N=1,000 atoms and the spectrum linewidth γ=8 Hz. The relative stability reaches 1×10-17 with an averaging time of 1,600 s. Finally, we discuss the prospects to realize 10-18 fractional inaccuracies and the possible application of frequency comparison with synchronous interrogations to remote clocks' comparison for relativistic geodesy.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 8, 2011•0 citations
Optical lattice clocks with uncertainty and instability in the 10􀀀17-range and below have so far been demonstrated exclusively using fermions. Here, we demonstrate a bosonic optical lattice clock with 3 10􀀀18 instability and 2:0 10􀀀17 accuracy, both values improving on previous work by a factor 30. This was enabled by probing the clock transition with an ultra-long interrogation time of 4 s, using the long coherence time provided by a cryogenic silicon resonator, by careful stabilization of relevant operating parameters, and by operating at low atom density. This work demonstrates that bosonic clocks, in combination with highly coherent interrogation lasers, are suitable for highaccuracy applications with particular requirements, such as high reliability, transportability, operation in space, or suitability for particular fundamental physics topics. As an example, we determine the 88Sr { 87Sr isotope shift with 12 mHz uncertainty.
Optical clocks are being developed worldwide and are at the forefront of frequency metrology. Today they outperform microwave clocks instability and inaccuracy by two orders of magnitude, raising discussion about the redefinition of the SI second. Their outstanding performances are paving the way to applications in different fields apart from metrology. Optical clocks can be used for geodetic measurements, such as chronometric levelling, and fundamental physics experiments. These applications require transportable, and even space-born optical clocks that are in development. Space optical clocks will serve as a high accurate references for intercontinental clock comparisons, and will also provide a unique test bench for fundamental physics theories, such as Einstein’s prediction of time dilation and equivalence principle. This work presents the development and characterization of a transportable strontium optical lattice clock, realised in the framework of the ESA I-SOC (Space Optical Clock on the ISS) mission. The aim of the project is to investigate new technologies and techniques, in order to develop a robust apparatus as demonstrator for space applications. Special effort has been made to reduce the size and weight of the clock, so as to meet the stringent requirements of a space mission. The system reported here is one of the most compact optical clock to date, with a total volume of only 1 m3, excluding electronics. The clock is operated with the strontium bosonic isotope 88Sr: this is preferable to the fermionic counterpart 87Sr, commonly used in optical lattice clocks, if simplicity and reliability are required. However, in terms of accuracy, bosonic clocks present some disadvantages compared with the fermionic ones, which have significantly slowed down their development for metrological applications. We characterised the relevant operating parameters and their effect on the clock accuracy and instability. Exploiting a clock laser offering an outstanding stability, we were able to demonstrate a clock fractional instability of 3×10-18 , and an inaccuracy of 2×10-17: both values represent a factor of 30 improvement compared with previous works on bosonic optical clocks. These results suggest that, in the near future, bosonic clocks may become competitive to their fermionic counterparts. This is of interest for applications such as time scale realization, transportable clocks, or for test of fundamental physics. As an example, we measured the 88Sr-87Sr isotope shift, with an uncertainty of 12 mHz.
Optical clocks operated on satellites are expected to open up new opportunities in time transfer, geodesy, fundamental physics, and satellite navigation. Here we demonstrate an important first step towards this goal: a modular, compact, optical lattice clock (OLC) system that achieves $2.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ fractional uncertainty. The clock is operated with bosonic strontium and improves the performance of bosonic OLCs by a factor of 30. This has important implications for future use of bosonic OLCs in fundamental physics and metrology. We make use of the clock's metrological performance to measure, with independent clocks, the isotope shift of the $^{1}S_{0}\ensuremath{\rightarrow}^{3}P_{0}$ transitions of 88Sr^{88}\mathrm{Sr}88Sr and 87Sr^{87}\mathrm{Sr}87Sr, with an uncertainty of 12 mHz. The ratio of the transition frequencies is thus determined with $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ fractional uncertainty.
We discuss two possible configurations for optical lattice clocks; a one-dimensional (1D) lattice loaded with spinpolarized fermions, and a three-dimensional (3D) lattice loaded with bosons. In the former scheme, collisional frequency shifts are suppressed by the quantum statistical property of identical fermions. This Pauli blocking of collisions is critically dependent on the degree of spin polarization of the fermionic atoms, which we carefully investigated in the Rabi excitation process of the clock transition. In the latter scheme, a single occupancy lattice suppresses bunching of bosons and collisional frequency shifts. We demonstrate a frequency comparison of these two optical lattice clocks based on fermionic 87Sr and bosonic 88Sr. Operating these clocks parallely has yielded a stability approaching 10−17. Such measurements are an important step to ascertain the lattice clocks' uncertainty at the 10−17 level and beyond.
An optical lattice clock probes a spectrally narrow electronic transition in an ensemble of optically trapped, laser-cooled atoms, for use as a time and frequency standard. To date, several lattice clocks have been demonstrated with superior stability and accuracy compared to primary frequency standards based on microwave transitions. Yet, the question of which atomic system (including the element and isotope) performs best as a lattice clock remains unsettled. This thesis describes the first detailed investigation of an optical lattice clock using a spin-1/2 isotope of the ytterbium atom. A spin-1/2 system possesses several advantages over higher-spin systems, including a simplified level structure (allowing for straightforward manipulation of the nuclear spin state) and the absence of any tensor light shift from the confining optical lattice. Moreover, the ytterbium atom (Yb) stands among the leading lattice clock candidates, offering a high-performance optical clock with some degree of experimental simplicity. The frequency stability of the Yb clock is highlighted by resolving an ultra-narrow clock spectrum with a full-width at half-maximum of 1 Hz, corresponding to a record quality factor Q = ν0/Δν = 5 × 1014. Moreover, this system can be highly accurate, which is demonstrated by characterizing the Yb clock frequency at the 3 × 10-16 level of fractional uncertainty, with further progress toward a ten-fold improvement also presented. To reach this low level of uncertainty required careful consideration of important systematic errors, including the identification of the Stark-canceling wavelength, where the clock’s sensitivity to the lattice intensity is minimized, a precise determination of the static polarizability of the clock transition, and the measurement and control of atom-atom collisions.
Abstract We present several developments aimed at improving the stability of optical lattice clocks. First, we present our developments of an optical lattice clock using neutral mercury. We mention recent advances made with the fermionic isotope 199Hg. We also mention our work aimed at using bosonic isotopes, which offer the possibility to circumvent the relatively short lifetime of the upper clock state in 199Hg. Second, we present our work on a non-destructive detection in a Sr optical lattice clock. We describe developments that brought the detection scheme from the classical non-destructive regime to the quantum non-destructive regime. Our detection scheme is practical and has the capability to the used beyond proving the principle. Finally, we present our work on laser stabilization using spectral hole burning in a Eu3+:Y2SiO5 crystal at cryogenic temperatures. We describe our development of low noise interrogation based on digital IQ modulation and detection that can probe multiple spectral features simultaneously, as well as several investigations towards fluctuating environmental factors. These advances, individually or combined for example with spectral purity transfer with combs and composite clock approaches, shall bring significant progress in clock stability and accuracy.
We demonstrate the frequency comparison of two optical lattice clocks at the relative stabilities close to the quantum projection noise (QPN) limit of optical lattice clocks. This stable frequency comparison is accomplished by synchronous interrogations of two clocks by a common probe laser, which allows us to cancel out the probe laser's frequency noise. We perform the frequency comparison of a one-dimensional (1D) optical lattice clock with spin-polarized fermions 87Sr and a three-dimensional (3D) optical lattice clock with unity-occupation bosons 88Sr and achieve the Allan standard deviation of σγ(τ)=4×10-16 τ-1/2, which corresponds to the QPN limited stability for N=1,000 atoms and the spectrum linewidth γ=8 Hz. The relative stability reaches 1×10-17 with an averaging time of 1,600 s. Finally, we discuss the prospects to realize 10-18 fractional inaccuracies and the possible application of frequency comparison with synchronous interrogations to remote clocks' comparison for relativistic geodesy.