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Saidi S, Alharzali N, Berriche H. A combining rule calculation of the ground-state van der Waals potentials of the magnesium rare-gas complexes. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1292368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Samah Saidi
- Laboratory of Interfaces and Advanced Materials, Physics Department, Faculty of Science, University of Monastir, Monastir, Tunisia
| | - Nissrin Alharzali
- Laboratory of Interfaces and Advanced Materials, Physics Department, Faculty of Science, University of Monastir, Monastir, Tunisia
| | - Hamid Berriche
- Laboratory of Interfaces and Advanced Materials, Physics Department, Faculty of Science, University of Monastir, Monastir, Tunisia
- Department of Mathematics and Natural Sciences, School of Arts and Science, American University of Ras Al Khaimah, Ras Al Khaimah, UAE
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2
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Affiliation(s)
- Hendrick L. Bethlem
- a FOM-Institute for Plasma Physics Rijnhuizen , P.O. Box 1207, Nieuwegein , NL-3430 BE , The Netherlands
| | - Gerard Meijer
- b FOM-Institute for Plasma Physics Rijnhuizen , P.O. Box 1207, Nieuwegein , NL-3430 BE , The Netherlands
- c Department of Molecular and Laser Physics , University of Nijmegen , Toernooiveld 1, Nijmegen , NL-6525 ED , The Netherlands
- d Fritz Haber Institut-Max-Planck-Gesellschaft , Faradayweg 4-6, Berlin , D-14195 , Germany
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3
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Bouissou T, Durand G, Heitz MC, Spiegelman F. A comprehensive theoretical investigation of the electronic states of Ca2 up to the Ca(4s(2) 1S) + Ca(4s5p 1P) dissociation limit. J Chem Phys 2010; 133:164317. [PMID: 21033798 DOI: 10.1063/1.3503655] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A theoretical survey of the electronic structure of Ca(2) is presented using two-electron pseudopotentials complemented by core-polarization operators on Ca atoms and multireference configuration interaction/quasidegenerate perturbation theory (MRCI/QDPT) treatment of molecular excited states. The spectroscopic constants of 70 electronic states up to 30,000 cm(-1) above the ground state are determined. This implies all Ca(2) states dissociating up to the Ca(4s(2) (1)S) + Ca(4s5p (3,1)P) dissociation limits. All spin states (singlet, triplet, and quintet) are investigated. The work emphasizes the variety of interactions implying singly valence and lowest Rydberg excited states, doubly excited states generated by atom pairs (3)P(4s4p) + (3)P(4s4p), or (3)P(4s4p) + (3)D(4s3d), 4p3d double excitations asymptotically localized on a single-atom. Zwitterionic Ca(+) + Ca(-) configurations are evidenced and shown to induce specific electronic patterns in (1)Σ(g)(+), (3)Σ(g)(+), (1)Σ(u)(+), (3)Σ(u)(+), (1)Π(g), (3)Π(g), (1)Π(u), and (3)Π(u) symmetry manifolds. They also provide insight for qualitative features (barriers) found for the lower electronic states already investigated in previous publications by other authors.
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Affiliation(s)
- Thomas Bouissou
- Laboratoire de Chimie et Physique Quantiques/IRSAMC, Université de Toulouse (UPS) and CNRS, 118 route de Narbonne, F-31062 Toulouse Cedex, France
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Yang DD, Li P, Tang KT. The ground state van der Waals potentials of the calcium dimer and calcium rare-gas complexes. J Chem Phys 2009; 131:154301. [DOI: 10.1063/1.3246351] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Kraft S, Vogt F, Appel O, Riehle F, Sterr U. Bose-Einstein condensation of alkaline earth atoms: ;{40}Ca. PHYSICAL REVIEW LETTERS 2009; 103:130401. [PMID: 19905493 DOI: 10.1103/physrevlett.103.130401] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Indexed: 05/28/2023]
Abstract
We have achieved Bose-Einstein condensation of ;{40}Ca, the first for an alkaline earth element. The influence of elastic and inelastic collisions associated with the large ground-state s-wave scattering length of ;{40}Ca was measured. From these findings, an optimized loading and cooling scheme was developed that allowed us to condense about 2 x 10;{4} atoms after laser cooling in a two-stage magneto-optical trap and subsequent forced evaporation in a crossed dipole trap within less than 3 s. The condensation of an alkaline earth element opens novel opportunities for precision measurements on the narrow intercombination lines as well as investigations of molecular states at the ;{1}S-;{3}P asymptotes.
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Affiliation(s)
- Sebastian Kraft
- Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, Germany.
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6
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Mitroy J, Zhang JY. Properties and long range interactions of the calcium atom. J Chem Phys 2008; 128:134305. [DOI: 10.1063/1.2841470] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Bussery-Honvault B, Launay JM, Korona T, Moszynski R. Theoretical spectroscopy of the calcium dimer in the A 1Sigma(u)+, c3Pi(u), and a3Sigma(u)+ manifolds: an ab initio nonadiabatic treatment. J Chem Phys 2006; 125:114315. [PMID: 16999482 DOI: 10.1063/1.2222348] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Nonadiabatic theory of molecular spectra of diatomic molecules is presented. It is shown that in the fully nonadiabatic framework, the rovibrational wave functions describing the nuclear motions in diatomic molecules can be obtained from a system of coupled differential equations. The rovibrational wave functions corresponding to various electronic states are coupled through the relativistic spin-orbit coupling interaction and through different radial and angular coupling terms, while the transition intensities can be written in terms of the ground state rovibrational wave function and bound rovibrational wave functions of all excited electronic states that are electric dipole connected with the ground state. This theory was applied in the nearly exact nonadiabatic calculations of energy levels, line positions, and intensities of the calcium dimer in the A (1)Sigma(u) (+)(1 (1)S+1 (1)D), c (3)Pi(u)(1 (3)P+1 (1)S), and a (3)Sigma(u) (+)(1 (3)P+1 (1)S) manifolds of states. The excited state potentials were computed using a combination of the linear response theory within the coupled-cluster singles and doubles framework for the core-core and core-valence electronic correlations and of the full configuration interaction for the valence-valence correlation, and corrected for the one-electron relativistic terms resulting from the first-order many-electron Breit theory. The electric transition dipole moment governing the A (1)Sigma(u) (+)<--X (1)Sigma(g) (+) transitions was obtained as the first residue of the frequency-dependent polarization propagator computed with the coupled-cluster method restricted to single and double excitations, while the spin-orbit and nonadiabatic coupling matrix elements were computed with the multireference configuration interaction wave functions restricted to single and double excitations. Our theoretical results explain semiquantitatively all the features of the observed Ca(2) spectrum in the A (1)Sigma(u) (+)(1 (1)S+1 (1)D), c (3)Pi(u)(1 (3)P+1 (1)S), and a (3)Sigma(u) (+)(1 (3)P+1 (1)S) manifolds of states.
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Affiliation(s)
- Béatrice Bussery-Honvault
- Laboratoire PALMS, UMR 6627 du CNRS, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
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Tojo S, Kitagawa M, Enomoto K, Kato Y, Takasu Y, Kumakura M, Takahashi Y. High-resolution photoassociation spectroscopy of ultracold ytterbium atoms by using the intercombination transition. PHYSICAL REVIEW LETTERS 2006; 96:153201. [PMID: 16712155 DOI: 10.1103/physrevlett.96.153201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Indexed: 05/09/2023]
Abstract
We observed high-resolution photoassociation spectra of laser-cooled ytterbium (Yb) atoms in the spin-forbidden 1S0 - 3P1 intercombination line. The rovibrational levels in the 0u+ state were measured for red detunings of the photoassociation laser ranging from 2.9 MHz to 1.97 GHz with respect to the atomic resonance. The rotational splitting of the vibrational levels near the dissociation limit were fully resolved due to the sub-MHz linewidth of the spectra in contrast to previous measurements using the spin-allowed singlet transition. In addition, from a comparison between the spectra of 174Yb and those of 176Yb, a d-wave shape resonance for 174Yb is strongly suggested.
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Affiliation(s)
- Satoshi Tojo
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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Kallush S, Segev B, Côté R. Evanescent-wave mirror for ultracold diatomic polar molecules. PHYSICAL REVIEW LETTERS 2005; 95:163005. [PMID: 16241795 DOI: 10.1103/physrevlett.95.163005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Indexed: 05/05/2023]
Abstract
We describe the interaction of an ultracold diatomic polar molecule with an evanescent-wave mirror. Several features of this system are explored, such as the coupling between internal rovibrational states of the molecule and the laser field. Numerical simulations show quantum reflection and state selection under attainable physical conditions. Such molecular optics components will facilitate the manipulation and trapping of ultracold molecules, and might serve in future applications in several fields, e.g., as devices to filter and select a state for ultracold chemistry, to measure extremely low temperatures of molecules, or to manipulate states for quantum information processing.
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Affiliation(s)
- S Kallush
- Fritz-Haber Research Center, Hebrew University, Jerusalem, Israel
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Pichler M, Chen H, Stwalley WC. Photoassociation spectroscopy of ultracold Cs below the 6P(3/2) limit. J Chem Phys 2004; 121:6779-84. [PMID: 15473735 DOI: 10.1063/1.1788657] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
High precision photoassociation spectroscopy is performed in ultracold cesium gas, with detunings as large as 51 cm(-1) below the Cs(6S(1/2))+Cs(6P(3/2)) asymptote. Trap-loss fluorescence detection is used for detecting the photoassociation to excited state ultracold molecules. Long vibrational progressions are assigned to electronic states of 0(g) (-), 0(u) (+), and 1(g) symmetry. The spectral data are fitted to a LeRoy-Bernstein equation, in order to obtain the effective coefficients of the leading long-range interaction term (C(3)/R(3)) and the relative vibrational quantum numbers measured down from dissociation. Additionally we present evidence for perturbations between the 0(g) (-) state and the dark 2(u) state.
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Affiliation(s)
- Marin Pichler
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
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11
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Dulieu O, Pillet P. Playing With a Pair of Ultracold Atoms and Lasers: Towards a Novel Ultracold Photochemistry? Isr J Chem 2004. [DOI: 10.1560/rhhr-c4m6-pffn-8a8j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Takasu Y, Komori K, Honda K, Kumakura M, Yabuzaki T, Takahashi Y. Photoassociation spectroscopy of laser-cooled ytterbium atoms. PHYSICAL REVIEW LETTERS 2004; 93:123202. [PMID: 15447261 DOI: 10.1103/physrevlett.93.123202] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Indexed: 05/24/2023]
Abstract
We report the photoassociation spectroscopy of laser-cooled ytterbium atoms in an optical trap. We observed more than 90 photoassociation resonances of vibrational levels in the (1)Sigma(+)(u) state, including 80 consecutive series, up to 490 GHz detuning with respect to the atomic resonance. From the resonance frequencies we derived the atomic radiative lifetime of the (6s6p) 1P1 state to be 5.464+/-0.005 ns, which is about 2 orders of magnitude improvement over previous results. We also observed line broadening of resonances, which is ascribed to the predissociation to the triplet states, and estimated the transition probability to be 0.2. Furthermore, we observed the decrease of the photoassociation signal intensity, from which the scattering length is estimated to be equal to or less than 3 nm.
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Affiliation(s)
- Y Takasu
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto, Japan 606-8502
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Pichler M, Chen H, Stwalley WC. Photoassociation spectroscopy of ultracold Cs below the 6P1/2 limit. J Chem Phys 2004; 121:1796-801. [PMID: 15260730 DOI: 10.1063/1.1767071] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have performed high precision photoassociation spectroscopy of ultracold cesium gas. Using trap-loss fluorescence detection and controlling the background cesium pressure we were able to photoassociate atoms into excited states of ultracold molecules with large detunings up to 56 cm(-1) below the Cs(6S(1/2)) + Cs(6P(1/2)) atomic asymptote. Vibrational progressions are assigned to 0(g)(-), 0(u)(+), and 1(g) long-range states. By fitting the spectral data to the LeRoy-Bernstein expression, the effective coefficients of the leading long-range interactions and the vibrational quantum number at dissociation are obtained. In addition we have observed spectral perturbations between states of the same symmetry belonging to different asymptotes (6P(1/2) and 6P(3/2)). The perturbations are manifested through irregular vibrational level spacings and are especially pronounced in the 0(u)(+) symmetry. Many observed rotational levels indicate d- and higher partial wave contributions to the photoassociation cross section in the presence of trapping laser light, while spectral regions with only weak features suggest nodes in the lower state wave functions corresponding to the two ground state atoms asymptote.
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Affiliation(s)
- Marin Pichler
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
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Ribeiro E, Zanelatto A, Napolitano R. High-intensity and ground-state influence on photoassociation line shapes of 88Sr. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.03.150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Comparat D. Improved LeRoy–Bernstein near-dissociation expansion formula, and prospect for photoassociation spectroscopy. J Chem Phys 2004; 120:1318-29. [PMID: 15268257 DOI: 10.1063/1.1626539] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
NDE (Near-dissociation expansion) including LeRoy-Bernstein formulas are improved by taking into account the multipole expansion coefficients and the nonasymptotic part of the potential curve. The theory is tested with the Rydberg-Klein-Rees (RKR) potential curve of the Cs(2)(0(g) (-)6s+6p(3/2)) state. Results indicate that the formula could be used to improve the determination of the asymptotic coefficient (within a 1% accuracy) and to extract relativistic correction from photoassociation spectra of long-range potential curve of diatomic molecules.
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Affiliation(s)
- Daniel Comparat
- Laboratoire Aime Cotton, CNRS II, Bat. 505, Campus d'Orsay, 91405 Orsay cedex, France.
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Kokoouline V, Santra R, Greene CH. Multichannel cold collisions between metastable Sr atoms. PHYSICAL REVIEW LETTERS 2003; 90:253201. [PMID: 12857129 DOI: 10.1103/physrevlett.90.253201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2003] [Indexed: 05/24/2023]
Abstract
We present a multichannel-scattering calculation of elastic and inelastic cold collisions between two low-field seeking, metastable 88Sr [(5s5p)3P2] atoms in the presence of an external magnetic field. The scattering physics is governed by strong anisotropic long-range interactions, which lead to pronounced coupling among the partial waves of relative motion. As a result, nonadiabatic transitions are shown to trigger a high rate of inelastic losses. At relatively high energies, T>100 microK, the total inelastic collision rate is comparable with the elastic rate. However, at lower collisional energy, the elastic rate decreases, and at T approximately 1 microK, it becomes substantially smaller than the inelastic rate. Our study suggests that magnetic trapping and evaporative cooling of 88Sr [(5s5p)3P2] atoms, as well as 40Ca [(4s4p)3P2], in low-field seeking states will prove difficult to achieve experimentally.
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Courtillot I, Quessada A, Kovacich RP, Zondy JJ, Landragin A, Clairon A, Lemonde P. Efficient cooling and trapping of strontium atoms. OPTICS LETTERS 2003; 28:468-470. [PMID: 12659282 DOI: 10.1364/ol.28.000468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report the capture of cold strontium atoms in a magneto-optical trap (MOT) at a rate of 4 x 10(10) atoms/s. The MOT is loaded from an atomic beam decelerated by a Zeeman slower operating with a focused laser beam. The 461-nm laser, used for both cooling and trapping, was generated by sum-frequency mixing in a KTP crystal with diode lasers at 813 nm and a Nd:YAG laser at 1064 nm. As much as 115 mW of blue light was obtained.
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Affiliation(s)
- I Courtillot
- Bureau National de Métrologie-Systèmes de Référence Temps Espace, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8630, Observatoire de Paris, 61 Avenue de l'Observatoire, 75014 Paris, France
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Binnewies T, Wilpers G, Sterr U, Riehle F, Helmcke J, Mehlstäubler TE, Rasel EM, Ertmer W. Doppler cooling and trapping on forbidden transitions. PHYSICAL REVIEW LETTERS 2001; 87:123002. [PMID: 11580503 DOI: 10.1103/physrevlett.87.123002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2001] [Indexed: 05/23/2023]
Abstract
Ultracold atoms at temperatures close to the recoil limit have been achieved by extending Doppler cooling to forbidden transitions. A cloud of (40)Ca atoms has been cooled and trapped to a temperature as low as 6 microK by operating a magnetooptical trap on the spin-forbidden intercombination transition. Quenching the long-lived excited state with an additional laser enhanced the scattering rate by a factor of 15, while a high selectivity in velocity was preserved. With this method, more than 10% of precooled atoms from a standard magnetooptical trap have been transferred to the ultracold trap. Monte Carlo simulations of the cooling process are in good agreement with the experiments.
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Affiliation(s)
- T Binnewies
- Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany
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