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Tiedau J, Okhapkin MV, Zhang K, Thielking J, Zitzer G, Peik E, Schaden F, Pronebner T, Morawetz I, De Col LT, Schneider F, Leitner A, Pressler M, Kazakov GA, Beeks K, Sikorsky T, Schumm T. Laser Excitation of the Th-229 Nucleus. Phys Rev Lett 2024; 132:182501. [PMID: 38759160 DOI: 10.1103/physrevlett.132.182501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/12/2024] [Accepted: 03/14/2024] [Indexed: 05/19/2024]
Abstract
The 8.4 eV nuclear isomer state in Th-229 is resonantly excited in Th-doped CaF_{2} crystals using a tabletop tunable laser system. A resonance fluorescence signal is observed in two crystals with different Th-229 dopant concentrations, while it is absent in a control experiment using Th-232. The nuclear resonance for the Th^{4+} ions in Th:CaF_{2} is measured at the wavelength 148.3821(5) nm, frequency 2020.409(7) THz, and the fluorescence lifetime in the crystal is 630(15) s, corresponding to an isomer half-life of 1740(50) s for a nucleus isolated in vacuum. These results pave the way toward Th-229 nuclear laser spectroscopy and realizing optical nuclear clocks.
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Affiliation(s)
- J Tiedau
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
| | - M V Okhapkin
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
| | - K Zhang
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
| | - J Thielking
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
| | - G Zitzer
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
| | - E Peik
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
| | - F Schaden
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - T Pronebner
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - I Morawetz
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - L Toscani De Col
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - F Schneider
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - A Leitner
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - M Pressler
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - G A Kazakov
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - K Beeks
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - T Sikorsky
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - T Schumm
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
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Ayyash HF, Ogundele MO, Schumm T, Mitrofan O. G625 Collaboration between community child health and child/adolescent mental health services in the UK: results from a national survey. ADHD and related neurodevelopmental disorders – george still forum 2020. [DOI: 10.1136/archdischild-2020-rcpch.539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Pimon M, Gugler J, Mohn P, Kazakov GA, Mauser N, Schumm T. DFT calculation of 229thorium-doped magnesium fluoride for nuclear laser spectroscopy. J Phys Condens Matter 2020; 32:255503. [PMID: 32131054 DOI: 10.1088/1361-648x/ab7c90] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The 229thorium nucleus has an extremely low-energy isomeric state that could be manipulated with light in the vacuum ultraviolet (VUV) range. Recent measurements based on internal conversion electrons place the isomer energy at 8.28(17) eV (Seiferle B et al 2019), within the transmission window of large-band-gap materials, such as fluoride single crystals. Doping 229Th into VUV-transparent materials realizes a spectroscopy target with a high nuclei density and might form the basis of a solid-state nuclear clock. This paper presents a theoretical study of the optical properties of a thorium-doped MgF2 crystal. Using the Vienna Ab-initio Simulation Package, we perform density functional theory calculations of the electronic and optical properties of Th:MgF2. We determine whether thorium will be accepted as a dopant and identify the charge compensation mechanism and geometry. The simulations indicate, that the band gap of Th-doped MgF2 will be significantly reduced compared to undoped MgF2, below the expected 229Th isomer energy. This result is in striking contrast to a similar study performed for Th-doped CaF2 (Dessovic P et al 2014 J. Phys. Condens. Matter 26 105402).
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Affiliation(s)
- M Pimon
- Center for Computational Materials Science, TU Wien, Wiedner Hauptstraße 8-10/134, Austria
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Seres J, Seres E, Serrat C, Young EC, Speck JS, Schumm T. All-solid-state VUV frequency comb at 160 nm using high-harmonic generation in nonlinear femtosecond enhancement cavity. Opt Express 2019; 27:6618-6628. [PMID: 30876243 DOI: 10.1364/oe.27.006618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
We realized a solid-state-based vacuum ultraviolet frequency comb by harmonics generation in an external enhancement cavity. Optical conversions were so far reported by only using gaseous media. We present a theory that allows the most suited solid generation medium to be selected for specific target harmonics by adapting the material's bandgap. We experimentally use a thin AlN film grown on a sapphire substrate to realize a compact frequency comb high-harmonic source in the Deep Ultraviolet (DUV) / Vacuum Ultraviolet (VUV) spectral range. By extending our earlier VUV source [Opt. Express26, 21900 (2018)] with the enhancement cavity, a sub-Watt level Ti:sapphire femtosecond frequency comb is enhanced to 24 W stored average power, its 3rd, 5th, and 7th harmonics are generated, and the targeted 5th harmonic's power at 160 nm increased by two orders of magnitude. The emerging nonlinear effects in the solid medium, together with suitable intra-cavity dispersion management, support optimal enhancement and stable locking. To demonstrate the realized frequency comb's spectroscopic ability, we report on the beat measurement between the 3rd harmonic beam and a 266 nm CW laser reaching about 1 MHz accuracy.
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Seres J, Seres E, Serrat C, Schumm T. Non-perturbative generation of DUV/VUV harmonics from crystal surfaces at 108 MHz repetition rate. Opt Express 2018; 26:21900-21909. [PMID: 30130892 DOI: 10.1364/oe.26.021900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate non-perturbative 3rd (267 nm) and 5th (160 nm) harmonic generation in solids from a Ti:sapphire frequency comb (800 nm) at 108 MHz repetition rate. The experiments show that non-perturbative low harmonics are dominantly generated on the surface and on the interface between solids, and that they are not produced by bulk processes from the near-surface layer of the material. Measurements reveal that due to the lack of phase matching, the generated harmonics in bulk are suppressed by orders of magnitude compared to the signal generated on the surface. Our results pave the way for the development of all-solid-state high repetition rate harmonic sources for vacuum ultraviolet spectroscopy and high precision frequency comb metrology.
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van Frank S, Negretti A, Berrada T, Bücker R, Montangero S, Schaff JF, Schumm T, Calarco T, Schmiedmayer J. Interferometry with non-classical motional states of a Bose-Einstein condensate. Nat Commun 2014; 5:4009. [PMID: 24874019 PMCID: PMC4050268 DOI: 10.1038/ncomms5009] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/29/2014] [Indexed: 11/23/2022] Open
Abstract
The Ramsey interferometer is a prime example of precise control at the quantum level. It is usually implemented using internal states of atoms, molecules or ions, for which powerful manipulation procedures are now available. Whether it is possible to control external degrees of freedom of more complex, interacting many-body systems at this level remained an open question. Here we demonstrate a two-pulse Ramsey-type interferometer for non-classical motional states of a Bose-Einstein condensate in an anharmonic trap. The control sequences used to manipulate the condensate wavefunction are obtained from optimal control theory and are directly optimized to maximize the interferometric contrast. They permit a fast manipulation of the atomic ensemble compared to the intrinsic decay processes and many-body dephasing effects. This allows us to reach an interferometric contrast of 92% in the experimental implementation.
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Affiliation(s)
- S. van Frank
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, A-1020 Vienna, Austria
| | - A. Negretti
- Zentrum für Optische Quantentechnologien, Universität Hamburg, The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany
- Institut für Quanteninformationsverarbeitung, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - T. Berrada
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, A-1020 Vienna, Austria
| | - R. Bücker
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, A-1020 Vienna, Austria
- Max Planck Institute for the Structure and Dynamics of Matter, Bldg. 99 (CFEL), Luruper Chaussee 149, D-22761 Hamburg, Germany
| | - S. Montangero
- Institut für Quanteninformationsverarbeitung, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
- Center for Integrated Quantum Science and Technology (IQST), Universität of Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - J.-F. Schaff
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, A-1020 Vienna, Austria
| | - T. Schumm
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, A-1020 Vienna, Austria
| | - T. Calarco
- Institut für Quanteninformationsverarbeitung, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
- Center for Integrated Quantum Science and Technology (IQST), Universität of Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - J. Schmiedmayer
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, A-1020 Vienna, Austria
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Dessovic P, Mohn P, Jackson RA, Winkler G, Schreitl M, Kazakov G, Schumm T. 229Thorium-doped calcium fluoride for nuclear laser spectroscopy. J Phys Condens Matter 2014; 26:105402. [PMID: 24553189 DOI: 10.1088/0953-8984/26/10/105402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The (229)thorium isotope presents an extremely low-energy isomer state of the nucleus which is expected around 7.8 eV, in the vacuum ultraviolet (VUV) regime. This unique system may bridge between atomic and nuclear physics, enabling coherent manipulation and precision spectroscopy of nuclear quantum states using laser light. It has been proposed to implant (229)thorium into VUV transparent crystal matrices to facilitate laser spectroscopy and possibly realize a solid-state nuclear clock. In this work, we validate the feasibility of this approach by computer modelling of thorium doping into calcium fluoride single crystals. Using atomistic modelling and full electronic structure calculations, we find a persistent large band gap and no additional electronic levels emerging in the middle of the gap due to the presence of the dopant, which should allow direct optical interrogation of the nuclear transition.Based on the electronic structure, we estimate the thorium nuclear quantum levels within the solid-state environment. Precision laser spectroscopy of these levels will allow the study of a broad range of crystal field effects, transferring Mössbauer spectroscopy into the optical regime.
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Affiliation(s)
- P Dessovic
- Center for Computational Materials Science, Vienna University of Technology, Gusshausstrasse 25/134, A-1040, Vienna, Austria
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Kazakov G, Schauer V, Schwestka J, Stellmer S, Sterba J, Fleischmann A, Gastaldo L, Pabinger A, Enss C, Schumm T. Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter. Nucl Instrum Methods Phys Res A 2014; 735:229-239. [PMID: 25844000 PMCID: PMC4376067 DOI: 10.1016/j.nima.2013.09.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 09/06/2013] [Accepted: 09/08/2013] [Indexed: 06/04/2023]
Abstract
The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8±0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.
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Affiliation(s)
- G.A. Kazakov
- Wolfgang Pauli Institute, Univ. Wien – UZA 4 Nordbergstrasse 15, A, 1090 Vienna, Austria
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
| | - V. Schauer
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
| | - J. Schwestka
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
| | - S.P. Stellmer
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
| | - J.H. Sterba
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
| | - A. Fleischmann
- Kirchhoff-Institute for Physics, Heidelberg University, INF 227, 69120 Heidelberg, Germany
| | - L. Gastaldo
- Kirchhoff-Institute for Physics, Heidelberg University, INF 227, 69120 Heidelberg, Germany
| | - A. Pabinger
- Kirchhoff-Institute for Physics, Heidelberg University, INF 227, 69120 Heidelberg, Germany
| | - C. Enss
- Kirchhoff-Institute for Physics, Heidelberg University, INF 227, 69120 Heidelberg, Germany
| | - T. Schumm
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria
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Betz T, Manz S, Bücker R, Berrada T, Koller C, Kazakov G, Mazets IE, Stimming HP, Perrin A, Schumm T, Schmiedmayer J. Two-point phase correlations of a one-dimensional bosonic Josephson junction. Phys Rev Lett 2011; 106:020407. [PMID: 21405210 DOI: 10.1103/physrevlett.106.020407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 12/10/2010] [Indexed: 05/30/2023]
Abstract
We realize a one-dimensional Josephson junction using quantum degenerate Bose gases in a tunable double well potential on an atom chip. Matter wave interferometry gives direct access to the relative phase field, which reflects the interplay of thermally driven fluctuations and phase locking due to tunneling. The thermal equilibrium state is characterized by probing the full statistical distribution function of the two-point phase correlation. Comparison to a stochastic model allows us to measure the coupling strength and temperature and hence a full characterization of the system.
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Affiliation(s)
- T Betz
- Vienna Center for Quantum Science and Technology, Atominstitut, TU-Wien, 1020 Vienna, Austria
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Abstract
Optical dipole traps and atom chips are two very powerful tools for the quantum manipulation of neutral atoms. We demonstrate that both methods can be combined by creating an optical lattice potential on an atom chip. A red-detuned laser beam is retroreflected using the atom chip surface as a high-quality mirror, generating a vertical array of purely optical oblate traps. We transfer thermal atoms from the chip into the lattice and observe cooling into the two-dimensional regime. Using a chip-generated Bose-Einstein condensate, we demonstrate coherent Bloch oscillations in the lattice.
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Affiliation(s)
- D Gallego
- Physikalisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany
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Mazets IE, Schumm T, Schmiedmayer J. Breakdown of integrability in a quasi-1D ultracold bosonic gas. Phys Rev Lett 2008; 100:210403. [PMID: 18518588 DOI: 10.1103/physrevlett.100.210403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 05/01/2008] [Indexed: 05/26/2023]
Abstract
We demonstrate that virtual excitations of higher radial modes in an atomic Bose gas in a tightly confining waveguide result in effective three-body collisions that violate integrability in this quasi-one-dimensional quantum system and give rise to thermalization. The estimated thermalization rates are consistent with recent experimental results in quasi-1D dynamics of ultracold atoms.
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Affiliation(s)
- I E Mazets
- Atominstitut der Osterreichischen Universitäten, TU Wien, A-1020 Vienna, Austria
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Hofferberth S, Lesanovsky I, Fischer B, Schumm T, Schmiedmayer J. Non-equilibrium coherence dynamics in one-dimensional Bose gases. Nature 2007; 449:324-7. [PMID: 17882216 DOI: 10.1038/nature06149] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Accepted: 08/02/2007] [Indexed: 11/09/2022]
Abstract
Low-dimensional systems provide beautiful examples of many-body quantum physics. For one-dimensional (1D) systems, the Luttinger liquid approach provides insight into universal properties. Much is known of the equilibrium state, both in the weakly and strongly interacting regimes. However, it remains a challenge to probe the dynamics by which this equilibrium state is reached. Here we present a direct experimental study of the coherence dynamics in both isolated and coupled degenerate 1D Bose gases. Dynamic splitting is used to create two 1D systems in a phase coherent state. The time evolution of the coherence is revealed through local phase shifts of the subsequently observed interference patterns. Completely isolated 1D Bose gases are observed to exhibit universal sub-exponential coherence decay, in excellent agreement with recent predictions. For two coupled 1D Bose gases, the coherence factor is observed to approach a non-zero equilibrium value, as predicted by a Bogoliubov approach. This coupled-system decay to finite coherence is the matter wave equivalent of phase-locking two lasers by injection. The non-equilibrium dynamics of superfluids has an important role in a wide range of physical systems, such as superconductors, quantum Hall systems, superfluid helium and spin systems. Our experiments studying coherence dynamics show that 1D Bose gases are ideally suited for investigating this class of phenomena.
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Affiliation(s)
- S Hofferberth
- Physikalisches Institut, Universität Heidelberg, Philosophenweg 12, D-69120 Heidelberg, Germany
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Esteve J, Trebbia JB, Schumm T, Aspect A, Westbrook CI, Bouchoule I. Observations of density fluctuations in an elongated Bose gas: ideal gas and quasicondensate regimes. Phys Rev Lett 2006; 96:130403. [PMID: 16711971 DOI: 10.1103/physrevlett.96.130403] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Indexed: 05/09/2023]
Abstract
We report in situ measurements of density fluctuations in a quasi-one-dimensional 87Rb Bose gas at thermal equilibrium in an elongated harmonic trap. We observe an excess of fluctuations compared to the shot-noise level expected for uncorrelated atoms. At low atomic density, the measured excess is in good agreement with the expected "bunching" for an ideal Bose gas. At high density, the measured fluctuations are strongly reduced compared to the ideal gas case. We attribute this reduction to repulsive interatomic interactions. The data are compared with a calculation for an interacting Bose gas in the quasicondensate regime.
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Affiliation(s)
- J Esteve
- Laboratoire Charles Fabry, CNRS et Université Paris Sud 11, 91403 Orsay Cedex, France
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Kasper A, Schneider S, Hagen CV, Bartenstein M, Engeser B, Schumm T, Bar-Joseph I, Folman R, Feenstra L, Schmiedmayer J. A Bose Einstein condensate in a microtrap. ACTA ACUST UNITED AC 2003. [DOI: 10.1088/1464-4266/5/2/372] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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