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Giannakeas P, Melezhik VS, Schmelcher P. Dipolar confinement-induced resonances of ultracold gases in waveguides. PHYSICAL REVIEW LETTERS 2013; 111:183201. [PMID: 24237514 DOI: 10.1103/physrevlett.111.183201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Indexed: 06/02/2023]
Abstract
We develop a nonperturbative theoretical framework to treat collisions with generic anisotropic interactions in quasi-one-dimensional geometries. Our method avoids the limitations of pseudopotential theory and allows us to include accurately long-range anisotropic interactions. For ultracold dipolar collisions in a harmonic waveguide we predict dipolar confinement-induced resonances (DCIRs) which are attributed to different angular momentum states. The analytically derived resonance condition reveals in detail the interplay of the confinement with the anisotropic nature of the dipole-dipole interactions. The results are in excellent agreement with ab initio numerical calculations confirming the robustness of the presented approach. The exact knowledge of the positions of DCIRs may pave the way for the experimental realization of, e.g., Tonks-Girardeau-like or super-Tonks-Girardeau-like phases in effective one-dimensional dipolar gases.
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Affiliation(s)
- P Giannakeas
- Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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2
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Jensen BB, Ming H, Westergaard PG, Gunnarsson K, Madsen MH, Brusch A, Hald J, Thomsen JW. Experimental determination of the ²⁴Mg I (3s3p)³P₂ lifetime. PHYSICAL REVIEW LETTERS 2011; 107:113001. [PMID: 22026659 DOI: 10.1103/physrevlett.107.113001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Indexed: 05/31/2023]
Abstract
We present the first experimental determination of the electric-dipole forbidden (3s3p)³P₂→(3s²)¹S₀ (M2) transition rate in ²⁴Mg and compare to state-of-the-art theoretical predictions. Our measurement exploits a magnetic trap isolating the sample from perturbations and a magneto-optical trap as an amplifier converting each ³P₂→¹S₀ decay event into millions of photons readily detected. The transition rate is determined to be (4.87 ± 0.3)×10⁻⁴ s⁻¹ corresponding to a ³P₂ lifetime of 2050(-110)(+140) sec. This value is in agreement with recent theoretical predictions, and to our knowledge the longest lifetime ever determined in a laboratory environment.
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Affiliation(s)
- B B Jensen
- The Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen, Denmark
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3
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Lonij VPA, Klauss CE, Holmgren WF, Cronin AD. Atom diffraction reveals the impact of atomic core electrons on atom-surface potentials. PHYSICAL REVIEW LETTERS 2010; 105:233202. [PMID: 21231458 DOI: 10.1103/physrevlett.105.233202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Indexed: 05/30/2023]
Abstract
We measured ratios of van der Waals potential coefficients (C3) for different atoms (Li, Na, K, and Rb) interacting with the same surface by studying atom diffraction from a nanograting. These measurements are a sensitive test of atomic structure calculations because C3 ratios are strongly influenced by core electrons and only weakly influenced by the permittivity and geometry of the surface. Our measurement uncertainty of 2% in the ratio C(3)(K)/C(3)(Na) is close to the uncertainty of the best theoretical predictions, and some of these predictions are inconsistent with our measurement.
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Affiliation(s)
- Vincent P A Lonij
- Department of Physics, University of Arizona, Tucson, Arizona 85721, USA
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4
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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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5
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McFerran JJ, Yi L, Mejri S, Bize S. Sub-Doppler cooling of fermionic Hg isotopes in a magneto-optical trap. OPTICS LETTERS 2010; 35:3078-3080. [PMID: 20847784 DOI: 10.1364/ol.35.003078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Laser cooling and trapping of neutral mercury is performed in a single-stage (1)S(0)↔(3)P(1) 3D magneto-optical trap. We give a detailed account of the atom cloud size and temperature for both bosonic ((200)Hg and (202)Hg) and fermionic ((199)Hg and (201)Hg) isotopes. The bosonic isotope temperatures are in close agreement with Doppler cooling theory, while temperatures obtained for the fermionic isotopes are lower, suggesting the presence of sub-Doppler cooling. A minimum temperature of 29±4 μK is achieved for (201)Hg.
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Affiliation(s)
- J J McFerran
- LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 Avenue de l'Observatoire, 75014 Paris, France.
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7
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Yin GP, Li P, Tang KT. The ground state van der Waals potentials of the strontium dimer and strontium rare-gas complexes. J Chem Phys 2010; 132:074303. [DOI: 10.1063/1.3317406] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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8
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Yamaguchi A, Uetake S, Hashimoto D, Doyle JM, Takahashi Y. Inelastic collisions in optically trapped ultracold metastable ytterbium. PHYSICAL REVIEW LETTERS 2008; 101:233002. [PMID: 19113544 DOI: 10.1103/physrevlett.101.233002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Indexed: 05/27/2023]
Abstract
We report measurement of inelastic loss in dense and cold metastable ytterbium (Yb[3P2]). Use of an optical far-off-resonance trap enables us to trap atoms in all magnetic sublevels, removing m-changing collisional trap loss from the system. Trapped samples of Yb[3P2] are produced at a density of 2 x 10(13) cm(-3) and temperature of 2 microK. We observe rapid two-body trap loss of Yb[3P2] and measure the inelastic collision rate constant 1.0(3) x 10(-11) cm3 s(-1). The existence of the fine-structure changing collisions between atoms in the 3P2 state is strongly suggested.
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Affiliation(s)
- A Yamaguchi
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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9
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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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10
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Poli N, Ferrari G, Prevedelli M, Sorrentino F, Drullinger RE, Tino GM. Laser sources for precision spectroscopy on atomic strontium. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2006; 63:981-6. [PMID: 16527534 DOI: 10.1016/j.saa.2005.10.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Revised: 10/02/2005] [Accepted: 10/09/2005] [Indexed: 05/07/2023]
Abstract
We present a new laser setup designed for high-precision spectroscopy on laser cooled atomic strontium. The system, which is entirely based on semiconductor laser sources, delivers 200 mW at 461 nm for cooling and trapping atomic strontium from a thermal source, 4 mW at 497 nm for optical pumping from the metastable P23 state, 12 mW at 689 nm on linewidth less than 1 kHz for second-stage cooling of the atomic sample down to the recoil limit, 1.2 W at 922 nm for optical trapping close to the "magic wavelength" for the 0-1 intercombination line at 689 nm. The 689 nm laser was already employed to perform a frequency measurement of the 0-1 intercombination line with a relative accuracy of 2.3 x 10(-11), and the ensemble of laser sources allowed the loading in a conservative dipole trap of multi-isotopes strontium mixtures. The simple and compact setup developed represents one of the first steps towards the realization of a transportable optical standards referenced to atomic strontium.
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Affiliation(s)
- N Poli
- Dipartimento di Fisica and LENS, Instituto Nazionale di Fisica Nucleare, Sezione di Firenze, Italy
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11
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Hansen D, Hemmerich A. Observation of multichannel collisions of cold metastable calcium atoms. PHYSICAL REVIEW LETTERS 2006; 96:073003. [PMID: 16606083 DOI: 10.1103/physrevlett.96.073003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Indexed: 05/08/2023]
Abstract
Recent theoretical work indicates that collisions between metastable alkaline-earth atoms (AEAs) in the presence of external magnetic fields should be largely determined by partial waves with large angular momenta even at very low temperatures. Unusually large inelastic collision cross sections were predicted and doubts have been raised regarding the feasibility of evaporative cooling of metastable AEAs in magnetic traps. Here we present experimental data for 40Ca[4s4p]3 P2 clearly confirming the asserted multichannel character of the collision mechanism. While elastic cross sections are found to be similar to the predicted values, inelastic cross sections exceed the calculations by an order of magnitude. Our results substantiate the expectation of inefficient evaporative cooling.
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Affiliation(s)
- Dirk Hansen
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
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12
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Nagel SB, Mickelson PG, Saenz AD, Martinez YN, Chen YC, Killian TC, Pellegrini P, Côté R. Photoassociative spectroscopy at long range in ultracold strontium. PHYSICAL REVIEW LETTERS 2005; 94:083004. [PMID: 15783889 DOI: 10.1103/physrevlett.94.083004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 02/18/2005] [Indexed: 05/24/2023]
Abstract
We report photoassociative spectroscopy of 88Sr(2) in a magneto-optical trap operating on the 1S0-->3P1 intercombination line at 689 nm. Photoassociative transitions are driven with a laser red detuned by 600-2400 MHz from the 1S0-->1P1 atomic resonance at 461 nm. Photoassociation takes place at extremely large internuclear separation, and the photoassociative spectrum is strongly affected by relativistic retardation. A fit of the transition frequencies determines the 1P1 atomic lifetime (tau=5.22+/-0.03 ns) and resolves a discrepancy between experiment and recent theoretical calculations.
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Affiliation(s)
- S B Nagel
- Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77251, USA
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13
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Yasuda M, Katori H. Lifetime measurement of the 3P2 metastable state of strontium atoms. PHYSICAL REVIEW LETTERS 2004; 92:153004. [PMID: 15169283 DOI: 10.1103/physrevlett.92.153004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Indexed: 05/24/2023]
Abstract
We have measured the lifetime of the 5s5p 3P2 metastable state of strontium atoms by magneto-optically trapping the decayed atoms to the ground state, which allowed sensitive detection of the rare decay events. We found that the blackbody radiation-induced decay was the dominant decay channel for the state at T=300 K. The lifetime was determined to be 520(+310)(-140) s in the limit of zero temperature, arguably the longest lifetime ever determined in a laboratory environment.
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Affiliation(s)
- Masami Yasuda
- Engineering Research Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
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Krems RV, Dalgarno A. Quantum-mechanical theory of atom-molecule and molecular collisions in a magnetic field: Spin depolarization. J Chem Phys 2004; 120:2296-307. [PMID: 15268368 DOI: 10.1063/1.1636691] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A theory for quantum-mechanical calculations of cross sections for atom-molecule and molecular collisions in a magnetic field is presented. The formalism is based on the representation of the wave function as an expansion in a fully uncoupled space-fixed basis. The systems considered include 1S-atom-2Sigma-molecule, 1S-atom-3Sigma-molecule, 2Sigma-molecule-2Sigma-molecule, and 3Sigma-molecule-3Sigma-molecule. The theory is used to elucidate the mechanisms for collisionally induced spin depolarization.
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Affiliation(s)
- R V Krems
- Harvard-MIT Center for Ultracold Atoms, Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
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Ferrari G, Cancio P, Drullinger R, Giusfredi G, Poli N, Prevedelli M, Toninelli C, Tino GM. Precision frequency measurement of visible intercombination lines of strontium. PHYSICAL REVIEW LETTERS 2003; 91:243002. [PMID: 14683113 DOI: 10.1103/physrevlett.91.243002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Indexed: 05/24/2023]
Abstract
We report the direct frequency measurement of the visible 5s(2) 1S0-5s5p 3P1 intercombination line of strontium that is considered a possible candidate for a future optical-frequency standard. The frequency of a cavity-stabilized laser is locked to the saturated fluorescence in a thermal Sr atomic beam and is measured with an optical-frequency comb generator referenced to the SI second through a global positioning system signal. The 88Sr transition is measured to be at 434 829 121 311 (10) kHz. We measure also the 88Sr-86Sr isotope shift to be 163 817.4 (0.2) kHz.
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Affiliation(s)
- G Ferrari
- Dipartimento di Fisica and LENS, Università di Firenze, INFM-UdR Firenze, Polo Scientifico, 50019 Sesto Fiorentino, Italy
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Takasu Y, Maki K, Komori K, Takano T, Honda K, Kumakura M, Yabuzaki T, Takahashi Y. Spin-singlet Bose-Einstein condensation of two-electron atoms. PHYSICAL REVIEW LETTERS 2003; 91:040404. [PMID: 12906649 DOI: 10.1103/physrevlett.91.040404] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2003] [Indexed: 05/24/2023]
Abstract
We report the observation of a Bose-Einstein condensation of ytterbium atoms by evaporative cooling in a novel crossed optical trap. Unlike the previously observed condensates, a ytterbium condensate is a two-electron system in a singlet state and has distinct features such as the extremely narrow intercombination transitions which are ideal for future optical frequency standard and the insensitivity to external magnetic field which is important for precision coherent atom optics, and the existence of the novel metastable triplet states generated by optical excitation from the singlet state.
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Affiliation(s)
- Yosuke Takasu
- Department of Physics, Graduate School of Science, Kyoto University, Japan 606-8502
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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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