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Scheidegger S, Merkt F. Precision-Spectroscopic Determination of the Binding Energy of a Two-Body Quantum System: The Hydrogen Atom and the Proton-Size Puzzle. PHYSICAL REVIEW LETTERS 2024; 132:113001. [PMID: 38563947 DOI: 10.1103/physrevlett.132.113001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/18/2024] [Accepted: 01/25/2024] [Indexed: 04/04/2024]
Abstract
Precision measurements in Rydberg states of H with principal quantum number n in the range between 20 and 30 are reported. In the presence of homogeneous electric fields with strengths below 2 V cm^{-1}, these Rydberg states are subject to a linear Stark effect with accurately calculable Stark shifts. From the spectral positions of field-independent and field-dependent Rydberg-Stark states, we derive the n=20 and 24 Bohr energies, and the ionization energy with respect to the 2 ^{2}S_{1/2}(f=0,1) [short 2S(0,1)] metastable states. Combining these results with the 2S(1)-1S(1) transition frequency [C. G. Parthey et al., Phys. Rev. Lett. 107, 203001 (2011)PRLTAO0031-900710.1103/PhysRevLett.107.203001; A. Matveev et al., Phys. Rev. Lett. 110, 230801 (2013)PRLTAO0031-900710.1103/PhysRevLett.110.230801] and the 1S hyperfine splitting [L. Essen et al., Nature (London) 229, 110 (1971)NATUAS0028-083610.1038/229110a0], we determine the ionization frequency of the 1S(0) ground state to be 3 288 087 922 407.2(3.7)_{stat}(1.8)_{syst} kHz, which is the most precise value ever determined for the binding energy of a two-body quantum system. Using the 2S(0)-2P_{1/2}(1) interval [N. Bezginov et al., Science 365, 1007 (2019)SCIEAS0036-807510.1126/science.aau7807], we determine the Rydberg frequency to be cR_{∞}=3 289 841 960 204(15)_{stat}(7)_{syst}(13)_{2S-2P} kHz in a procedure that is insensitive to the value of the proton charge radius. These new results are discussed in the context of the proton-size puzzle.
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Affiliation(s)
- Simon Scheidegger
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
- Quantum Center, ETH Zurich, Zurich 8093, Switzerland
| | - Frédéric Merkt
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
- Quantum Center, ETH Zurich, Zurich 8093, Switzerland
- Department of Physics, ETH Zurich, Zurich 8093, Switzerland
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Clausen G, Scheidegger S, Agner JA, Schmutz H, Merkt F. Imaging-Assisted Single-Photon Doppler-Free Laser Spectroscopy and the Ionization Energy of Metastable Triplet Helium. PHYSICAL REVIEW LETTERS 2023; 131:103001. [PMID: 37739364 DOI: 10.1103/physrevlett.131.103001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/21/2023] [Accepted: 08/14/2023] [Indexed: 09/24/2023]
Abstract
Skimmed supersonic beams provide intense, cold, collision-free samples of atoms and molecules and are one of the most widely used tools in atomic and molecular laser spectroscopy. High-resolution optical spectra are typically recorded in a perpendicular arrangement of laser and supersonic beams to minimize Doppler broadening. Typical Doppler widths are nevertheless limited to tens of MHz by the residual transverse-velocity distribution in the gas-expansion cones. We present an imaging method to overcome this limitation that exploits the correlation between the positions of the atoms and molecules in the supersonic expansion and their transverse velocities, and thus their Doppler shifts. With the example of spectra of (1s)(np) ^{3}P_{0-2}←(1s)(2s) ^{3}S_{1} transitions to high Rydberg states of metastable triplet He, we demonstrate the suppression of the residual Doppler broadening and a reduction of the full linewidths at half maximum to only about 1 MHz in the UV. Using a retroreflection arrangement for the laser beam and a cross-correlation method, we determine Doppler-free spectra without any signal loss from the selection, by imaging, of atoms within ultranarrow transverse-velocity classes. As an illustration, we determine the ionization energy of triplet metastable He and confirm the significant discrepancy between recent experimental [G. Clausen et al., Phys. Rev. Lett. 127, 093001 (2021)PRLTAO0031-900710.1103/PhysRevLett.127.093001] and high-level theoretical [V. Patkós et al., Phys. Rev. A 103, 042809 (2021)PLRAAN2469-992610.1103/PhysRevA.103.042809] values of this quantity.
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Affiliation(s)
- Gloria Clausen
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Simon Scheidegger
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Josef A Agner
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Hansjürg Schmutz
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Frédéric Merkt
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland
- Quantum Center, ETH Zurich, CH-8093 Zurich, Switzerland
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
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Noe S, Husmann D, Müller N, Morel J, Fichtner A. Long-range fiber-optic earthquake sensing by active phase noise cancellation. Sci Rep 2023; 13:13983. [PMID: 37633995 PMCID: PMC10460440 DOI: 10.1038/s41598-023-41161-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/22/2023] [Indexed: 08/28/2023] Open
Abstract
We present a long-range fiber-optic environmental deformation sensor based on active phase noise cancellation (PNC) in metrological frequency dissemination. PNC sensing exploits recordings of a compensation frequency that is commonly discarded. Without the need for dedicated measurement devices, it operates synchronously with metrological services, suggesting that existing phase-stabilized metrological networks can be co-used effortlessly as environmental sensors. The compatibility of PNC sensing with inline amplification enables the interrogation of cables with lengths beyond 1000 km, making it a potential contributor to earthquake detection and early warning in the oceans. Using spectral-element wavefield simulations that accurately account for complex cable geometry, we compare observed and computed recordings of the compensation frequency for a magnitude 3.9 earthquake in south-eastern France and a 123 km fiber link between Bern and Basel, Switzerland. The match in both phase and amplitude indicates that PNC sensing can be used quantitatively, for example, in earthquake detection and characterization.
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Affiliation(s)
- Sebastian Noe
- Institute of Geophysics, ETH Zurich, 8092, Zurich, Switzerland
| | - Dominik Husmann
- Swiss Federal Institute of Metrology, METAS, 3003, Bern-Wabern, Switzerland
| | - Nils Müller
- Institute of Geophysics, ETH Zurich, 8092, Zurich, Switzerland
| | - Jacques Morel
- Swiss Federal Institute of Metrology, METAS, 3003, Bern-Wabern, Switzerland
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Matusko M, Ryger I, Goavec-Merou G, Millo J, Lacroûte C, Carry É, Friedt JM, Delehaye M. Fully digital platform for local ultra-stable optical frequency distribution. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:034716. [PMID: 37012800 DOI: 10.1063/5.0138599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
This article reports on the use of a Field Programmable Gate Array (FPGA) platform for local ultra-stable optical frequency distribution through a 90 m-long fiber network. This platform is used to implement a fully digital treatment of the Doppler-cancellation scheme required by fiber links to be able to distribute ultra-stable frequencies. We present a novel protocol that uses aliased images of a digital synthesizer output to directly generate signals above the Nyquist frequency. This approach significantly simplifies the setup, making it easy to duplicate within a local fiber network. We demonstrate performances enabling the distribution of an optical signal with an instability below 10-17 at 1 s at the receiver end. We also use the board to implement an original characterization method. It leads to an efficient characterization of the disturbance rejection of the system that can be realized without accessing the remote output of the fiber link.
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Affiliation(s)
- Martina Matusko
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Ivan Ryger
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Gwenhaël Goavec-Merou
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Jacques Millo
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Clément Lacroûte
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Émile Carry
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Jean-Michel Friedt
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
| | - Marion Delehaye
- Université de Franche-Comté, SUPMICROTECH, CNRS, Institut FEMTO-ST, F-25000 Besançon, France
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Sinhal M, Johnson A, Willitsch S. Frequency stabilisation and SI tracing of mid-infrared quantum-cascade lasers for precision molecular spectroscopy. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2144519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Mudit Sinhal
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Anatoly Johnson
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Stefan Willitsch
- Department of Chemistry, University of Basel, Basel, Switzerland
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Cizek M, Pravdova L, Minh Pham T, Lesundak A, Hrabina J, Lazar J, Pronebner T, Aeikens E, Premper J, Havlis O, Velc R, Smotlacha V, Altmannova L, Schumm T, Vojtech J, Niessner A, Cip O. Coherent fibre link for synchronization of delocalized atomic clocks. OPTICS EXPRESS 2022; 30:5450-5464. [PMID: 35209507 DOI: 10.1364/oe.447498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Challenging experiments for tests in fundamental physics require highly coherent optical frequency references with suppressed phase noise from hundreds of kHz down to μHz of Fourier frequencies. It can be achieved by remote synchronization of many frequency references interconnected by stabilized optical fibre links. Here we describe the path to realize a delocalized optical frequency reference for spectroscopy of the isomeric state of the nucleus of Thorium-229 atom. This is a prerequisite for the realization of the next generation of an optical clock - the nuclear clock. We present the established 235 km long phase-coherent stabilized cross-border fibre link connecting two delocalized metrology laboratories in Brno and Vienna operating highly-coherent lasers disciplined by active Hydrogen masers through optical frequency combs. A significant part (up to tens of km) of the optical fibre is passing urban combined collectors with a non-negligible level of acoustic interference and temperature changes, which results in a power spectral density of phase noise over 105 rad2· Hz-1. Therefore, we deploy a digital signal processing technique to suppress the fibre phase noise over a wide dynamic range of phase fluctuations. To demonstrate the functionality of the link, we measured the phase noise power spectral density of a remote beat note between two independent lasers, locked to high-finesse stable resonators. Using optical frequency combs at both ends of the link, a long-term fractional frequency stability in the order of 10-15 between local active Hydrogen masers was measured as well. Thanks to this technique, we have achieved reliable operation of the phase-coherent fibre link with fractional stability of 7 × 10-18 in 103 s.
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