Options
Mileti, Gaetano
Nom
Mileti, Gaetano
Affiliation principale
Fonction
Professeur titulaire
Email
gaetano.mileti@unine.ch
Identifiants
Résultat de la recherche
Voici les éléments 1 - 10 sur 120
- PublicationAccès libreRoadmap towards the redefinition of the second(2024-01-22)
;N Dimarcq ;M Gertsvolf; ;S Bize ;C W Oates ;E Peik ;D Calonico ;T Ido ;P Tavella ;F Meynadier ;G Petit ;G Panfilo ;J Bartholomew ;P Defraigne ;E A Donley ;P O Hedekvist ;I Sesia ;M Wouters ;P Dubé ;F Fang ;F Levi ;J Lodewyck ;H S Margolis ;D Newell ;S Slyusarev ;S Weyers ;J-P Uzan ;M Yasuda ;D-H Yu ;C Rieck ;H Schnatz ;Y Hanado ;M Fujieda ;P-E Pottie ;J Hanssen ;A MalimonN AshbyThis paper outlines the roadmap towards the redefinition of the second, which was recently updated by the CCTF Task Force created by the CCTF in 2020. The main achievements of optical frequency standards (OFS) call for reflection on the redefinition of the second, but open new challenges related to the performance of the OFS, their contribution to time scales and UTC, the possibility of their comparison, and the knowledge of the Earth's gravitational potential to ensure a robust and accurate capacity to realize a new definition at the level of 10−18 uncertainty. The mandatory criteria to be achieved before redefinition have been defined and their current fulfilment level is estimated showing the fields that still needed improvement. The possibility to base the redefinition on a single or on a set of transitions has also been evaluated. The roadmap indicates the steps to be followed in the next years to be ready for a sound and successful redefinition. - PublicationAccès libreA cold-atom Ramsey clock with a low volume physics package(2024-01-09)
;Alan Bregazzi; ; ; ;Paul Griffin ;Ben LewisErling RiisWe demonstrate a Ramsey-type microwave clock interrogating the 6.835~GHz ground-state transition in cold \textsuperscript{87}Rb atoms loaded from a grating magneto-optical trap (GMOT) enclosed in an additively manufactured loop-gap resonator microwave cavity. A short-term stability of 1.5×10−11~τ−1/2 is demonstrated, in reasonable agreement with predictions from the signal-to-noise ratio of the measured Ramsey fringes. The cavity-grating package has a volume of ≈67~cm\textsuperscript{3}, ensuring an inherently compact system while the use of a GMOT drastically simplifies the optical requirements for laser cooled atoms. This work is another step towards the realisation of highly compact portable cold-atom frequency standards. - PublicationAccès libreAn additive-manufactured microwave cavity for a compact cold-atom clock(2023)
; ;Alan Bregazzi ;Ben Lewis ;Paul F. Griffin ;Erling Riis; We present an additive-manufactured microwave cavity for a Ramsey-type, double resonance, compact cold-atom clock. Atoms can be laser cooled inside the cavity using a grating magneto-optic trap with the cavity providing an excellent TE011-like mode while maintaining sufficient optical access for atomic detection. The cavity features a low Q-factor of 360 which conveniently reduces the cavity pulling of the future clock. Despite the potential porosity of the additive-manufacturing process, we demonstrate that the cavity is well-suited for vacuum. A preliminary clock setup using cold atoms allows for measuring the Zeeman spectrum and Rabi oscillations in the cavity which enables us to infer excellent field uniformity and homogeneity, respectively, across the volume accessed by the cold atoms. Ramsey spectroscopy is demonstrated, indicating that the cavity is suitable for clock applications. Finally, we discuss the limitations of the future clock. - PublicationAccès libreTechnology roadmap for cold-atoms based quantum inertial sensor in space(2023)
;Sven Abend ;Baptiste Allard ;Aidan S. Arnold ;Ticijana Ban ;Liam Barry ;Baptiste Battelier ;Ahmad Bawamia ;Quentin Beaufils ;Simon Bernon ;Andrea Bertoldi ;Alexis Bonnin ;Philippe Bouyer ;Alexandre Bresson ;Oliver S. Burrow ;Benjamin Canuel ;Bruno Desruelle ;Giannis Drougakis ;René Forsberg ;Naceur Gaaloul ;Alexandre Gauguet ;Matthias Gersemann ;Paul F. Griffin ;Hendrik Heine ;Victoria A. Henderson ;Waldemar Herr ;Simon Kanthak ;Markus Krutzik ;Maike D. Lachmann ;Roland Lammegger ;Werner Magnes; ;Morgan W. Mitchell ;Sergio Mottini ;Dimitris Papazoglou ;Franck Pereira dos Santos ;Achim Peters ;Ernst Rasel ;Erling Riis ;Christian Schubert ;Stephan Tobias Seidel ;Guglielmo M. Tino ;Mathias Van Den Bossche ;Wolf von Klitzing ;Andreas Wicht ;Marcin Witkowski ;Nassim ZahzamMichał ZawadaRecent developments in quantum technology have resulted in a new generation of sensors for measuring inertial quantities, such as acceleration and rotation. These sensors can exhibit unprecedented sensitivity and accuracy when operated in space, where the free-fall interrogation time can be extended at will and where the environment noise is minimal. European laboratories have played a leading role in this field by developing concepts and tools to operate these quantum sensors in relevant environment, such as parabolic flights, free-fall towers, or sounding rockets. With the recent achievement of Bose–Einstein condensation on the International Space Station, the challenge is now to reach a technology readiness level sufficiently high at both component and system levels to provide “off the shelf” payload for future generations of space missions in geodesy or fundamental physics. In this roadmap, we provide an extensive review on the status of all common parts, needs, and subsystems for the application of atom-based interferometers in space, in order to push for the development of generic technology components. - PublicationAccès libreA Microcell Atomic Clock Based on a Double-Resonance Ramsey Scheme(2022)
; ; ; ; ;Maddalena Violetti ;Yuanyan Su ;Anja K. Skrivervik - PublicationAccès libreGNSS-grade space atomic frequency standards: Current status and ongoing developments(2021)
; ; ; We present an overview on the current state of Global Navigation Satellite Systems (GNSS)-grade or better space atomic frequency standards’ (SAFS) technologies and discuss their applications. We estimate that a total of more than 1000 such standards were sent to space so far, the vast majority consisting of rubidium-cell frequency standards, Cs atomic beam frequency standards, and passive hydrogen masers. Finally, we review a variety of ongoing developments in view of future new generations of GNSS-grade SAFSs. - PublicationAccès libreLong-Term Stability Analysis Towards <10-14 Level for a Highly Compact POP Rb Cell Atomic ClockLong-term frequency instabilities in vapor-cell clocks mainly arise from fluctuations of the experimental and environmental parameters that are converted to clock frequency fluctuations via various physical processes. Here, we discuss the frequency sensitivities and the resulting stability limitations at one-day timescale for a rubidium vapor-cell clock based on a compact magnetron-type cavity operated in air (no vacuum environment). Under ambient laboratory conditions, the external atmospheric pressure fluctuations may dominantly limit the clock stability via the barometric effect. We establish a complete longterm instability budget for our clock operated under stable pressure conditions. Where possible, the fluctuations of experimental parameters are measured via the atomic response. The measured clock instability of <2 × 10-14 at one day is limited by the intensity light-shift effect, which could further be reduced by active stabilization of the laser intensity or stronger optical pumping. The analyses reported here show the way toward simple, compact, and low-power vapor-cell atomic clocks with excellent long-term stabilities ≤10-14 at one day when operated in ambient laboratory conditions.
- PublicationMétadonnées seulementLong-Term Stability Analysis Towards < 10-14 Level for a Highly Compact POP Rb Cell Atomic Clock(2019-4-14)
; ; ; ; Long-term frequency instabilities in vapor-cell clocks mainly arise from fluctuations of the experimental and environmental parameters that are converted to clock frequency fluctuations via various physical processes. Here, we discuss the frequency sensitivities and the resulting stability limitations at one day timescale for a rubidium vapor-cell clock based on a compact magnetron-type cavity operated in air (no vacuum environment). Under ambient laboratory conditions, the external atmospheric pressure fluctuations may dominantly limit the clock stability via the barometric effect. We establish a complete long-term instability budget for our clock operated under stable pressure conditions. Where possible, the fluctuations of experimental parameters are measured via the atomic response. The measured clock instability of < 2·E10.14 at one day is limited by the intensity light-shift effect, which could further be reduced by active stabilization of the laser intensity or stronger optical pumping. The analyses reported here show the way towards simple, compact, and low-power vapor-cell atomic clocks with excellent long-term stabilities. ≤ 10.14 at one day when operated in ambient laboratory conditions. - PublicationAccès libreImpact of microwave-field inhomogeneity in an alkali vapour cell using Ramsey double-resonance spectroscopyWe numerically and experimentally evaluate the impact of the inhomogeneity of the microwave field in the cavity used to perform double-resonance (DR) Ramsey spectroscopy in a buffer gas alkali vapour cell. The Ramsey spectrum is numerically simulated using a simple theoretical model and taking into account the field distribution in a magnetron-type microwave resonator. An experimental evaluation is performed using a DR pulsed optically pumped (POP) atomic clock. It is shown that the sensitivity to the micro-wave power of the DR POP clock can be reproduced from the combination of two inhomogeneities across the vapour cell: microwave field inhomogeneity and atomic ground-state resonance frequency inhomogeneity. Finally, we present the existence of an optimum operation point for which the microwave power sensitivity of our DR POP clock is reduced by two orders of magnitude. It leads into a long-term frequency stability of 1 × 10-14.
- PublicationAccès libre3D printed microwave cavity for atomic clock applications: proof of concept(2018-6-7)
; ; ; ;Skrivervik, A.K. ;Ivanov, A.E. ;Debogovic, T.de Rijk, E.The authors present the realisation and characterisation of an additively manufactured (AM) microwave resonator cavity for double-resonance (DR) vapour-cell atomic clocks. The design of the compact microwave cavity is based on the loop-gap resonator approach, previously demonstrated for conventionally-machined aluminium components. In the present study, the resonator is fabricated by AM using a metal-coated polymer. A resonance frequency at the desired 6.835 GHz rubidium atomic frequency is obtained. When employed in an atomic clock setup, the AM cavity enables a DR signal of <;500 Hz linewidth and of nearly 20% contrast, thus fulfilling the stringent requirements for DR atomic clocks. A clock short-term stability of 1 × 10 -12 τ -1/2 is demonstrated, comparable to state-of-the-art clock performances.