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Nonn Á, Margócsy Á, Mátyus E. Bound-State Relativistic Quantum Electrodynamics: A Perspective for Precision Physics with Atoms and Molecules. J Chem Theory Comput 2024. [PMID: 38789399 DOI: 10.1021/acs.jctc.4c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
Precision physics aims to use atoms and molecules to test and develop the fundamental theory of matter, possibly beyond the Standard Model. Most of the atomic and molecular phenomena are described by the quantum electrodynamics (QED) sector of the Standard Model. Do we have the computational tools, algorithms, and practical equations for the most possible complete computation of atoms and molecules within the QED sector? What is the fundamental equation to start with? Is it still Schrödinger's wave equation for molecular matter, or is there anything beyond that? This paper provides a concise overview of the relativistic QED framework and recent numerical developments targeting precision physics and spectroscopy applications with common features of the robust and successful relativistic quantum chemistry methodology.
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Affiliation(s)
- Ádám Nonn
- Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Ádám Margócsy
- Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Edit Mátyus
- Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
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2
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Imgram P, König K, Maaß B, Müller P, Nörtershäuser W. Collinear Laser Spectroscopy of 2 ^{3}S_{1}→2 ^{3}P_{J} Transitions in Helium-like ^{12}C^{4+}. PHYSICAL REVIEW LETTERS 2023; 131:243001. [PMID: 38181159 DOI: 10.1103/physrevlett.131.243001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/21/2023] [Indexed: 01/07/2024]
Abstract
Transition frequencies and fine-structure splittings of the 2 ^{3}S_{1}→2 ^{3}P_{J} transitions in helium-like ^{12}C^{4+} were measured by collinear laser spectroscopy on a 1-ppb level. Accuracy is increased by more than 3 orders of magnitude with respect to previous measurements, enabling tests of recent nonrelativistic (NR) QED calculations including terms up to mα^{7}. Deviations between the theoretical and experimental values are within theoretical uncertainties and are ascribed to mα^{8} and higher-order contributions in the series expansion of the NR QED calculations. Finally, prospects for an all-optical charge radius determination of light isotopes are evaluated.
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Affiliation(s)
- P Imgram
- Institut für Kernphysik, Departement of Physics, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
| | - K König
- Institut für Kernphysik, Departement of Physics, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
- Helmholtz Research Academy Hesse for FAIR, Campus Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
| | - B Maaß
- Institut für Kernphysik, Departement of Physics, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
| | - P Müller
- Institut für Kernphysik, Departement of Physics, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
| | - W Nörtershäuser
- Institut für Kernphysik, Departement of Physics, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
- Helmholtz Research Academy Hesse for FAIR, Campus Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
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3
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Magic wavelength for a rovibrational transition in molecular hydrogen. Sci Rep 2022; 12:14529. [PMID: 36008440 PMCID: PMC9411631 DOI: 10.1038/s41598-022-18159-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/05/2022] [Indexed: 11/11/2022] Open
Abstract
Molecular hydrogen, among other simple calculable atomic and molecular systems, possesses a huge advantage of having a set of ultralong living rovibrational states that make it well suited for studying fundamental physics. Further experimental progress will require trapping cold H2 samples. However, due to the large energy of the first electronic excitation, the conventional approach to finding a magic wavelength does not work for H2. We find a rovibrational transition for which the AC Stark shift is largely compensated by the interplay between the isotropic and anisotropic components of polarizability. The residual AC Stark shift can be completely eliminated by tuning the trapping laser to a specific “magic wavelength” at which the weak quadrupole polarizability cancels the residual dipole polarizability.
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4
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Henson BM, Ross JA, Thomas KF, Kuhn CN, Shin DK, Hodgman SS, Zhang YH, Tang LY, Drake GWF, Bondy AT, Truscott AG, Baldwin KGH. Measurement of a helium tune-out frequency: an independent test of quantum electrodynamics. Science 2022; 376:199-203. [PMID: 35389780 DOI: 10.1126/science.abk2502] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Despite quantum electrodynamics (QED) being one of the most stringently tested theories underpinning modern physics, recent precision atomic spectroscopy measurements have uncovered several small discrepancies between experiment and theory. One particularly powerful experimental observable that tests QED independently of traditional energy level measurements is the "tune-out" frequency, where the dynamic polarizability vanishes and the atom does not interact with applied laser light. In this work, we measure the tune-out frequency for the 23S1 state of helium between transitions to the 23P and 33P manifolds and compare it with new theoretical QED calculations. The experimentally determined value of 725,736,700(260) megahertz differs from theory [725,736,252(9) megahertz] by 1.7 times the measurement uncertainty and resolves both the QED contributions and retardation corrections.
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Affiliation(s)
- B M Henson
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - J A Ross
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - K F Thomas
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - C N Kuhn
- Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne, VIC 3122, Australia
| | - D K Shin
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - S S Hodgman
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - Yong-Hui Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
| | - Li-Yan Tang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
| | - G W F Drake
- Department of Physics, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - A T Bondy
- Department of Physics, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - A G Truscott
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - K G H Baldwin
- Department of Quantum Science and Technology, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
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5
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Clausen G, Jansen P, Scheidegger S, Agner JA, Schmutz H, Merkt F. Ionization Energy of the Metastable 2 ^{1}S_{0} State of ^{4}He from Rydberg-Series Extrapolation. PHYSICAL REVIEW LETTERS 2021; 127:093001. [PMID: 34506206 DOI: 10.1103/physrevlett.127.093001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
In a recent breakthrough in first-principles calculations of two-electron systems, Patkóś, Yerokhin, and Pachucki [Phys. Rev. A 103, 042809 (2021)PLRAAN2469-992610.1103/PhysRevA.103.042809] have performed the first complete calculation of the Lamb shift of the helium 2 ^{3}S_{1} and 2 ^{3}P_{J} triplet states up to the term in α^{7}m. Whereas their theoretical result of the frequency of the 2 ^{3}P←2 ^{3}S transition perfectly agrees with the experimental value, a more than 10σ discrepancy was identified for the 3 ^{3}D←2 ^{3}S and 3 ^{3}D←2 ^{3}P transitions, which hinders the determination of the He^{2+} charge radius from atomic spectroscopy. We present here a new measurement of the ionization energy of the 2 ^{1}S_{0} state of He [960 332 040.491(32) MHz] which we use in combination with the 2 ^{3}S_{1}←2 ^{1}S_{0} interval measured by Rengelink et al. [Nat. Phys. 14, 1132 (2018).NPAHAX1745-247310.1038/s41567-018-0242-5] and the 2 ^{3}P←2 ^{3}S_{1} interval measured by Zheng et al. [Phys. Rev. Lett. 119, 263002 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.263002] and Cancio Pastor et al. [Phys. Rev. Lett. 92, 023001 (2004)PRLTAO0031-900710.1103/PhysRevLett.92.023001] to derive experimental ionization energies of the 2 ^{3}S_{1} state [1152 842 742.640(32) MHz] and the 2 ^{3}P centroid energy [876 106 247.025(39) MHz]. These values reveal disagreements with the α^{7}m Lamb shift prediction by 6.5σ and 10σ, respectively, and support the suggestion by Patkóš et al. of an unknown theoretical contribution to the Lamb shifts of the 2 ^{3}S and 2 ^{3}P states of He.
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Affiliation(s)
- Gloria Clausen
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Paul Jansen
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Simon Scheidegger
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Josef A Agner
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Hansjürg Schmutz
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Frédéric Merkt
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
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6
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Affiliation(s)
- Maarten D. Hoogerland
- Department of Physics, Dodd-Walls Centre for Photonic and Quantum Technologies, University of Auckland, Auckland, New Zealand
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7
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Abstract
The technique of quantum electrodynamics (QED) calculations of energy levels in the helium atom is reviewed. The calculations start with the solution of the Schrödinger equation and account for relativistic and QED effects by perturbation expansion in the fine structure constant α. The nonrelativistic wave function is represented as a linear combination of basis functions depending on all three interparticle radial distances, r1, r2 and r = |r→1−r→2|. The choice of the exponential basis functions of the form exp(−αr1−βr2−γr) allows us to construct an accurate and compact representation of the nonrelativistic wave function and to efficiently compute matrix elements of numerous singular operators representing relativistic and QED effects. Calculations of the leading QED effects of order α5m (where m is the electron mass) are complemented with the systematic treatment of higher-order α6m and α7m QED effects.
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8
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Sixt T, Guan J, Tsoukala A, Hofsäss S, Muthu-Arachchige T, Stienkemeier F, Dulitz K. Preparation of individual magnetic sub-levels of 4He(2 3S 1) in a supersonic beam using laser optical pumping and magnetic hexapole focusing. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:073203. [PMID: 34340447 DOI: 10.1063/5.0048323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
We compare two different experimental techniques for the magnetic-sub-level preparation of metastable 4He in the 23S1 level in a supersonic beam, namely, magnetic hexapole focusing and optical pumping by laser radiation. At a beam velocity of v = 830 m/s, we deduce from a comparison with a particle trajectory simulation that up to 99% of the metastable atoms are in the MJ″ = +1 sub-level after magnetic hexapole focusing. Using laser optical pumping via the 23P2-23S1 transition, we achieve a maximum efficiency of 94% ± 3% for the population of the MJ″ = +1 sub-level. For the first time, we show that laser optical pumping via the 23P1-23S1 transition can be used to selectively populate each of the three MJ″ sub-levels (MJ″ = -1, 0, +1). We also find that laser optical pumping leads to higher absolute atom numbers in specific MJ″ sub-levels than magnetic hexapole focusing.
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Affiliation(s)
- Tobias Sixt
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Jiwen Guan
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Alexandra Tsoukala
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Simon Hofsäss
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | | | - Frank Stienkemeier
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Katrin Dulitz
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
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9
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Abstract
The redefined vacuum approach, which is frequently employed in the many-body perturbation theory, proved to be a powerful tool for formula derivation. Here, we elaborate this approach within the bound-state QED perturbation theory. In addition to general formulation, we consider the particular example of a single particle (electron or vacancy) excitation with respect to the redefined vacuum. Starting with simple one-electron QED diagrams, we deduce first- and second-order many-electron contributions: screened self-energy, screened vacuum polarization, one-photon exchange, and two-photon exchange. The redefined vacuum approach provides a straightforward and streamlined derivation and facilitates its application to any electronic configuration. Moreover, based on the gauge invariance of the one-electron diagrams, we can identify various gauge-invariant subsets within derived many-electron QED contributions.
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10
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Krauth JJ, Schuhmann K, Ahmed MA, Amaro FD, Amaro P, Biraben F, Chen TL, Covita DS, Dax AJ, Diepold M, Fernandes LMP, Franke B, Galtier S, Gouvea AL, Götzfried J, Graf T, Hänsch TW, Hartmann J, Hildebrandt M, Indelicato P, Julien L, Kirch K, Knecht A, Liu YW, Machado J, Monteiro CMB, Mulhauser F, Naar B, Nebel T, Nez F, dos Santos JMF, Santos JP, Szabo CI, Taqqu D, Veloso JFCA, Vogelsang J, Voss A, Weichelt B, Pohl R, Antognini A, Kottmann F. Measuring the α-particle charge radius with muonic helium-4 ions. Nature 2021; 589:527-531. [PMID: 33505036 PMCID: PMC7914124 DOI: 10.1038/s41586-021-03183-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/24/2020] [Indexed: 01/30/2023]
Abstract
The energy levels of hydrogen-like atomic systems can be calculated with great precision. Starting from their quantum mechanical solution, they have been refined over the years to include the electron spin, the relativistic and quantum field effects, and tiny energy shifts related to the complex structure of the nucleus. These energy shifts caused by the nuclear structure are vastly magnified in hydrogen-like systems formed by a negative muon and a nucleus, so spectroscopy of these muonic ions can be used to investigate the nuclear structure with high precision. Here we present the measurement of two 2S-2P transitions in the muonic helium-4 ion that yields a precise determination of the root-mean-square charge radius of the α particle of 1.67824(83) femtometres. This determination from atomic spectroscopy is in excellent agreement with the value from electron scattering1, but a factor of 4.8 more precise, providing a benchmark for few-nucleon theories, lattice quantum chromodynamics and electron scattering. This agreement also constrains several beyond-standard-model theories proposed to explain the proton-radius puzzle2-5, in line with recent determinations of the proton charge radius6-9, and establishes spectroscopy of light muonic atoms and ions as a precise tool for studies of nuclear properties.
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Affiliation(s)
- Julian J. Krauth
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany ,grid.5802.f0000 0001 1941 7111QUANTUM, Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, Mainz, Germany ,grid.12380.380000 0004 1754 9227Present Address: LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands
| | - Karsten Schuhmann
- grid.5801.c0000 0001 2156 2780Institute for Particle Physics and Astrophysics, ETH Zurich, Zurich, Switzerland ,grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Marwan Abdou Ahmed
- grid.5719.a0000 0004 1936 9713Institut für Strahlwerkzeuge, Universität Stuttgart, Stuttgart, Germany
| | - Fernando D. Amaro
- grid.8051.c0000 0000 9511 4342LIBPhys-UC, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Pedro Amaro
- grid.10772.330000000121511713Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of Physics, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - François Biraben
- grid.462576.40000 0004 0368 5631Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Paris, France
| | - Tzu-Ling Chen
- grid.38348.340000 0004 0532 0580Physics Department, National Tsing Hua University, Hsincho, Taiwan
| | - Daniel S. Covita
- grid.7311.40000000123236065i3N, Universidade de Aveiro, Aveiro, Portugal
| | - Andreas J. Dax
- grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Marc Diepold
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany
| | - Luis M. P. Fernandes
- grid.8051.c0000 0000 9511 4342LIBPhys-UC, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Beatrice Franke
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany ,grid.232474.40000 0001 0705 9791Present Address: TRIUMF, Vancouver, British Columbia Canada
| | - Sandrine Galtier
- grid.462576.40000 0004 0368 5631Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Paris, France ,grid.436142.60000 0004 0384 4911Present Address: Institut Lumière Matière, University of Lyon, Université Claude Bernard Lyon 1, CNRS, Villeurbanne, France
| | - Andrea L. Gouvea
- grid.8051.c0000 0000 9511 4342LIBPhys-UC, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Johannes Götzfried
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany
| | - Thomas Graf
- grid.5719.a0000 0004 1936 9713Institut für Strahlwerkzeuge, Universität Stuttgart, Stuttgart, Germany
| | - Theodor W. Hänsch
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany ,grid.5252.00000 0004 1936 973XLudwig-Maximilians-Universität, Fakultät für Physik, Munich, Germany
| | - Jens Hartmann
- grid.5252.00000 0004 1936 973XLudwig-Maximilians-Universität, Fakultät für Physik, Munich, Germany
| | - Malte Hildebrandt
- grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Paul Indelicato
- grid.462576.40000 0004 0368 5631Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Paris, France
| | - Lucile Julien
- grid.462576.40000 0004 0368 5631Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Paris, France
| | - Klaus Kirch
- grid.5801.c0000 0001 2156 2780Institute for Particle Physics and Astrophysics, ETH Zurich, Zurich, Switzerland ,grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Andreas Knecht
- grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Yi-Wei Liu
- grid.38348.340000 0004 0532 0580Physics Department, National Tsing Hua University, Hsincho, Taiwan
| | - Jorge Machado
- grid.10772.330000000121511713Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of Physics, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Cristina M. B. Monteiro
- grid.8051.c0000 0000 9511 4342LIBPhys-UC, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Françoise Mulhauser
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany
| | - Boris Naar
- grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Tobias Nebel
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany
| | - François Nez
- grid.462576.40000 0004 0368 5631Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Paris, France
| | - Joaquim M. F. dos Santos
- grid.8051.c0000 0000 9511 4342LIBPhys-UC, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - José Paulo Santos
- grid.10772.330000000121511713Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of Physics, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Csilla I. Szabo
- grid.462576.40000 0004 0368 5631Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Paris, France ,grid.421663.40000 0004 7432 9327Present Address: Theiss Research, La Jolla, CA USA
| | - David Taqqu
- grid.5801.c0000 0001 2156 2780Institute for Particle Physics and Astrophysics, ETH Zurich, Zurich, Switzerland ,grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | | | - Jan Vogelsang
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany ,grid.4514.40000 0001 0930 2361Present Address: Department of Physics, Lund University, Lund, Sweden
| | - Andreas Voss
- grid.5719.a0000 0004 1936 9713Institut für Strahlwerkzeuge, Universität Stuttgart, Stuttgart, Germany
| | - Birgit Weichelt
- grid.5719.a0000 0004 1936 9713Institut für Strahlwerkzeuge, Universität Stuttgart, Stuttgart, Germany
| | - Randolf Pohl
- grid.450272.60000 0001 1011 8465Max Planck Institute of Quantum Optics, Garching, Germany ,grid.5802.f0000 0001 1941 7111QUANTUM, Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Aldo Antognini
- grid.5801.c0000 0001 2156 2780Institute for Particle Physics and Astrophysics, ETH Zurich, Zurich, Switzerland ,grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
| | - Franz Kottmann
- grid.5801.c0000 0001 2156 2780Institute for Particle Physics and Astrophysics, ETH Zurich, Zurich, Switzerland ,grid.5991.40000 0001 1090 7501Paul Scherrer Institute, Villigen, Switzerland
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11
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Sun YR, Hu SM. Precision spectroscopy of atomic helium. Natl Sci Rev 2020; 7:1818-1827. [PMID: 34691519 PMCID: PMC8288801 DOI: 10.1093/nsr/nwaa216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/15/2019] [Accepted: 03/13/2020] [Indexed: 11/13/2022] Open
Abstract
Helium is a prototype three-body system and has long been a model system for developing quantum mechanics theory and computational methods. The fine-structure splitting in the 23P state of helium is considered to be the most suitable for determining the fine-structure constant α in atoms. After more than 50 years of efforts by many theorists and experimentalists, we are now working toward a determination of α with an accuracy of a few parts per billion, which can be compared to the results obtained by entirely different methods to verify the self-consistency of quantum electrodynamics. Moreover, the precision spectroscopy of helium allows determination of the nuclear charge radius, and it is expected to help resolve the 'proton radius puzzle'. In this review, we introduce the latest developments in the precision spectroscopy of the helium atom, especially the discrepancies among theoretical and experimental results, and give an outlook on future progress.
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Affiliation(s)
- Yu R Sun
- Hefei National Laboratory for Physical Sciences at Microscale, iChem Center, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Shui-Ming Hu
- Hefei National Laboratory for Physical Sciences at Microscale, iChem Center, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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12
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Thomas KF, Ross JA, Henson BM, Shin DK, Baldwin KGH, Hodgman SS, Truscott AG. Direct Measurement of the Forbidden 2^{3}S_{1}→3^{3}S_{1} Atomic Transition in Helium. PHYSICAL REVIEW LETTERS 2020; 125:013002. [PMID: 32678641 DOI: 10.1103/physrevlett.125.013002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
We present the detection of the highly forbidden 2^{3}S_{1}→3^{3}S_{1} atomic transition in helium, the weakest transition observed in any neutral atom. Our measurements of the transition frequency, upper state lifetime, and transition strength agree well with published theoretical values and can lead to tests of both QED contributions and different QED frameworks. To measure such a weak transition, we develop two methods using ultracold metastable (2^{3}S_{1}) helium atoms: low background direct detection of excited then decayed atoms for sensitive measurement of the transition frequency and lifetime, and a pulsed atom laser heating measurement for determining the transition strength. These methods could possibly be applied to other atoms, providing new tools in the search for ultraweak transitions and precision metrology.
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Affiliation(s)
- K F Thomas
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - J A Ross
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - B M Henson
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - D K Shin
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - K G H Baldwin
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - S S Hodgman
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - A G Truscott
- Laser Physics Centre, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
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