1
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Zhao MM, Wang BB, Han YC. Full-dimensional quantum mechanical study of
He3+He3+X− → He3+He3X−(X=HorD). PHYSICAL REVIEW RESEARCH 2022; 4:013030. [DOI: 10.1103/physrevresearch.4.013030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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2
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Manikandan N, Radhakrishnan R. Generating multibreather vector solitons by influencing the Manakov model and its modified forms with the linear self and cross coupling parameters. Heliyon 2018; 4:e00950. [PMID: 30839844 PMCID: PMC6251022 DOI: 10.1016/j.heliyon.2018.e00950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/09/2018] [Accepted: 11/15/2018] [Indexed: 11/28/2022] Open
Abstract
We have realized for the first time the multibreather vector multi-solitons supporting collision dynamics with many interaction effects (namely reflection, attraction, beating, etc., effects) associated with the coupled nonlinear Schrödinger family equations having multiple applications. Such effects can be suppressed or enhanced by using the soliton parameters. Here each colliding multibreather vector one-soliton is composed with many soliton and antisoliton parts. Our solutions have freedom to control the number of soliton and antisoliton parts used to compose a vector one-soliton with a definite breathing length. It is also interesting to observe that the breathing maps associated with the obtained solutions depend on their free parameters and also the system parameters. All such investigations help us to realize different breathing mechanisms (namely pedaling, toggling, symmetric compression, symmetric elongation, asymmetric compression, asymmetric elongation, etc.) supported by the colliding one-solitons. An existing breathing mechanism of a given vector breather one-soliton can be suppressed or switched into another mechanism by tuning certain parameters appropriately. Because of such features we believe that this kind of study will further give impetus on the Lindner-Fedyanin system in the continuum limit, and find the potential applications in fiber coupler and also in Bose-Einstein condensates.
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Affiliation(s)
- N. Manikandan
- Mount Zion College of Engineering and Technology, Pudukkottai - 622 507, Tamilnadu, India
| | - R. Radhakrishnan
- P.G. and Research Department of Physics, Jamal Mohamed College, Tiruchirappalli - 620 020, Tamilnadu, India
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3
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Rvachov TM, Son H, Park JJ, Ebadi S, Zwierlein MW, Ketterle W, Jamison AO. Two-photon spectroscopy of the NaLi triplet ground state. Phys Chem Chem Phys 2018; 20:4739-4745. [PMID: 29379932 DOI: 10.1039/c7cp08481a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We employ two-photon spectroscopy to study the vibrational states of the triplet ground state potential (a3Σ+) of the 23Na6Li molecule. Pairs of Na and Li atoms in an ultracold mixture are photoassociated into an excited triplet molecular state, which in turn is coupled to vibrational states of the triplet ground potential. Vibrational state binding energies, line strengths, and potential fitting parameters for the triplet ground a3Σ+ potential are reported. We also observe rotational splitting in the lowest vibrational state.
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Affiliation(s)
- Timur M Rvachov
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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4
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Rvachov TM, Son H, Sommer AT, Ebadi S, Park JJ, Zwierlein MW, Ketterle W, Jamison AO. Long-Lived Ultracold Molecules with Electric and Magnetic Dipole Moments. PHYSICAL REVIEW LETTERS 2017; 119:143001. [PMID: 29053331 DOI: 10.1103/physrevlett.119.143001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Indexed: 06/07/2023]
Abstract
We create fermionic dipolar ^{23}Na^{6}Li molecules in their triplet ground state from an ultracold mixture of ^{23}Na and ^{6}Li. Using magnetoassociation across a narrow Feshbach resonance followed by a two-photon stimulated Raman adiabatic passage to the triplet ground state, we produce 3×10^{4} ground state molecules in a spin-polarized state. We observe a lifetime of 4.6 s in an isolated molecular sample, approaching the p-wave universal rate limit. Electron spin resonance spectroscopy of the triplet state was used to determine the hyperfine structure of this previously unobserved molecular state.
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Affiliation(s)
- Timur M Rvachov
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Hyungmok Son
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Ariel T Sommer
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Sepehr Ebadi
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - Juliana J Park
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Martin W Zwierlein
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Wolfgang Ketterle
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Alan O Jamison
- Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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5
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Vexiau R, Borsalino D, Lepers M, Orbán A, Aymar M, Dulieu O, Bouloufa-Maafa N. Dynamic dipole polarizabilities of heteronuclear alkali dimers: optical response, trapping and control of ultracold molecules. INT REV PHYS CHEM 2017. [DOI: 10.1080/0144235x.2017.1351821] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- R. Vexiau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - D. Borsalino
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - M. Lepers
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - A. Orbán
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - M. Aymar
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - O. Dulieu
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
| | - N. Bouloufa-Maafa
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, Orsay Cedex, France
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6
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7
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Wang BB, Han YC, Cong SL. Role of sharp avoided crossings in short hyper-radial range in recombination of the cold 4He 3 system. J Chem Phys 2016; 145:204304. [PMID: 27908105 DOI: 10.1063/1.4968030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The role of sharp avoided crossings (SACs) in a short hyper-radial range R≤ 50 a.u. in the calculation of recombination for a cold 4He3 system is investigated in the adiabatic hyperspherical representation by "turning off and on" the relevant nonadiabatic couplings. The influence of SACs on the recombination is related with the channels of the system and with the scattering energy. For JΠ = 0+ symmetry, the two-body recombination channel has an attractive potential well, which makes radial wave functions of both two-body recombination channel and three-body continuum channels accessible in the short hyper-radial range where SACs are located. The SACs consequently play an important role in coupled-channel calculations and this is particularly the case for lower scattering energies. However, for excited nuclear orbital momenta, i.e., JΠ = 1-, 2+,…, 7- symmetries, the two-body recombination channel has a repulsive interaction and the radial wave functions are not accessible in the short hyper-radial range. Therefore, omission of SACs in the short range for these symmetries has no effect on the numerical results, which leads to great savings on hyper-radial grid points in the practical numerical calculations. Moreover, to make the nonadiabatic couplings among channels to be continuous in the hyper-radius, different methods associated with the application of consistent phase convention are discussed.
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Affiliation(s)
- Bin-Bin Wang
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China
| | - Yong-Chang Han
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China
| | - Shu-Lin Cong
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China
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8
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Frisch A, Mark M, Aikawa K, Baier S, Grimm R, Petrov A, Kotochigova S, Quéméner G, Lepers M, Dulieu O, Ferlaino F. Ultracold Dipolar Molecules Composed of Strongly Magnetic Atoms. PHYSICAL REVIEW LETTERS 2015; 115:203201. [PMID: 26613437 DOI: 10.1103/physrevlett.115.203201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 06/05/2023]
Abstract
In a combined experimental and theoretical effort, we demonstrate a novel type of dipolar system made of ultracold bosonic dipolar molecules with large magnetic dipole moments. Our dipolar molecules are formed in weakly bound Feshbach molecular states from a sample of strongly magnetic bosonic erbium atoms. We show that the ultracold magnetic molecules can carry very large dipole moments and we demonstrate how to create and characterize them, and how to change their orientation. Finally, we confirm that the relaxation rates of molecules in a quasi-two-dimensional geometry can be reduced by using the anisotropy of the dipole-dipole interaction and that this reduction follows a universal dipolar behavior.
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Affiliation(s)
- A Frisch
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - M Mark
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - K Aikawa
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - S Baier
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - R Grimm
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - A Petrov
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - S Kotochigova
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - G Quéméner
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France
| | - M Lepers
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France
| | - O Dulieu
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France
| | - F Ferlaino
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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9
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Renormalization group approach to the Fröhlich polaron model: application to impurity-BEC problem. Sci Rep 2015; 5:12124. [PMID: 26183614 PMCID: PMC4505313 DOI: 10.1038/srep12124] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/08/2015] [Indexed: 11/15/2022] Open
Abstract
When a mobile impurity interacts with a many-body system, such as a phonon bath, a polaron is formed. Despite the importance of the polaron problem for a wide range of physical systems, a unified theoretical description valid for arbitrary coupling strengths is still lacking. Here we develop a renormalization group approach for analyzing a paradigmatic model of polarons, the so-called Fröhlich model, and apply it to a problem of impurity atoms immersed in a Bose-Einstein condensate of ultra cold atoms. Polaron energies obtained by our method are in excellent agreement with recent diagrammatic Monte Carlo calculations for a wide range of interaction strengths. They are found to be logarithmically divergent with the ultra-violet cut-off, but physically meaningful regularized polaron energies are also presented. Moreover, we calculate the effective mass of polarons and find a smooth crossover from weak to strong coupling regimes. Possible experimental tests of our results in current experiments with ultra cold atoms are discussed.
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10
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Zheng W, Zhai H. Quasiparticle lifetime in a mixture of Bose and Fermi superfluids. PHYSICAL REVIEW LETTERS 2014; 113:265304. [PMID: 25615350 DOI: 10.1103/physrevlett.113.265304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Indexed: 06/04/2023]
Abstract
In this Letter, we study the effect of quasiparticle interactions in a Bose-Fermi superfluid mixture. We consider the lifetime of a quasiparticle of the Bose superfluid due to its interaction with quasiparticles in the Fermi superfluid. We find that this damping rate, i.e., the inverse of the lifetime, has quite a different threshold behavior at the BCS and the BEC side of the Fermi superfluid. The damping rate is a constant near the threshold momentum in the BCS side, while it increases rapidly in the BEC side. This is because, in the BCS side, the decay process is restricted by the constraint that the fermion quasiparticle is located near the Fermi surface, while such a restriction does not exist in the BEC side where the damping process is dominated by bosonic quasiparticles of the Fermi superfluid. Our results are related to the collective mode experiment in the recently realized Bose-Fermi superfluid mixture.
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Affiliation(s)
- Wei Zheng
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
| | - Hui Zhai
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
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11
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Yang Y, Liu X, Zhao Y, Xiao L, Jia S. Rovibrational Dynamics of RbCs on its Lowest 1,3Σ+ Potential Curves Calculated by Coupled Cluster Method with All-Electron Basis Set. J Phys Chem A 2012; 116:11101-6. [DOI: 10.1021/jp303975x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Yonggang Yang
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Xiaomeng Liu
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Yanting Zhao
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Liantuan Xiao
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics
and Quantum
Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
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12
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Song JL, Mashayekhi MS, Zhou F. Fermi-Bose mixtures near broad interspecies Feshbach resonances. PHYSICAL REVIEW LETTERS 2010; 105:195301. [PMID: 21231180 DOI: 10.1103/physrevlett.105.195301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 05/31/2010] [Indexed: 05/30/2023]
Abstract
In this Letter we study dressed bound states in Fermi-Bose mixtures near broad interspecies resonances, and implications on many-body correlations. We present the evidence for a first order phase transition between a mixture of Fermi gas and condensate, and a fully paired mixture where extended fermionic molecules occupy a single pairing channel instead of forming a molecular Fermi surface. We further investigate the effect of Fermi surface dynamics and pair fluctuations and discuss the validity of our results.
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Affiliation(s)
- Jun Liang Song
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, B.C., Canada V6T1Z1
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13
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Affiliation(s)
- Jeremy M. Hutson
- a Department of Chemistry , University of Durham , South Road, Durham , DH1 3LE , England
| | - Pavel Soldán
- b Faculty of Nuclear Sciences and Physical Engineering , Department of Physics , Doppler Institute , Czech Technical University , Břehová 7 , 115 19 Praha 1 , Czech Republic
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14
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Feiguin AE, Fisher MPA. Exotic paired states with anisotropic spin-dependent Fermi surfaces. PHYSICAL REVIEW LETTERS 2009; 103:025303. [PMID: 19659219 DOI: 10.1103/physrevlett.103.025303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/21/2009] [Indexed: 05/28/2023]
Abstract
We propose a model for realizing exotic paired states in cold Fermi gases by using a spin-dependent optical lattice to engineer mismatched Fermi surfaces for each hyperfine species. The BCS phase diagram shows a stable paired superfluid state with coexisting pockets of momentum space with gapless unpaired carriers, similar to the Sarma state in polarized mixtures, but in our case the system is unpolarized. We propose the possible existence of an exotic "Cooper-pair Bose-metal" phase, which has a gap for single fermion excitations but gapless and uncondensed "Cooper-pair" excitations residing on a "Bose surface" in momentum space.
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Affiliation(s)
- Adrian E Feiguin
- Microsoft Project Q, University of California, Santa Barbara, California 93106, USA
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15
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Sommer C, van Buuren LD, Motsch M, Pohle S, Bayerl J, Pinkse PWH, Rempe G. Continuous guided beams of slow and internally cold polar molecules. Faraday Discuss 2009; 142:203-20; discussion 221-55. [DOI: 10.1039/b819726a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Pellegrini P, Gacesa M, Côté R. Giant formation rates of ultracold molecules via Feshbach-optimized photoassociation. PHYSICAL REVIEW LETTERS 2008; 101:053201. [PMID: 18764389 DOI: 10.1103/physrevlett.101.053201] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Indexed: 05/26/2023]
Abstract
Ultracold molecules offer a broad variety of applications, ranging from metrology to quantum computing. However, forming "real" ultracold molecules, i.e., in deeply bound levels, is a very difficult proposition. Here, we show how photoassociation in the vicinity of a Feshbach resonance enhances molecular formation rates by several orders of magnitude. We illustrate this effect in heteronuclear systems, and find giant rate coefficients even in deeply bound levels. We also give a simple analytical expression for the photoassociation rate and discuss future applications of the Feshbach-optimized photoassociation technique.
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Affiliation(s)
- Philippe Pellegrini
- Department of Physics U-3046, University of Connecticut, Storrs, CT 06269-3046, USA
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17
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Yu Y, Yang K. Supersymmetry and the Goldstino-like mode in bose-fermi mixtures. PHYSICAL REVIEW LETTERS 2008; 100:090404. [PMID: 18352682 DOI: 10.1103/physrevlett.100.090404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Indexed: 05/26/2023]
Abstract
Supersymmetry is assumed to be a basic symmetry of the world in many high-energy theories, but none of the superpartners of any known elementary particle have been observed yet. We argue that supersymmetry can also be realized and studied in ultracold atomic systems with a mixture of bosons and fermions, with properly tuned interactions and single particle dispersion. We further show that in such nonrelativistic systems supersymmetry is either spontaneously broken or explicitly broken by a chemical potential difference between the bosons and fermions. In both cases the system supports a sharp fermionic collective mode similar to the Goldstino mode in high-energy physics, due to supersymmetry. We also discuss possible ways to detect this mode experimentally.
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Affiliation(s)
- Yue Yu
- Institute of Theoretical Physics, Chinese Academy of Sciences, PO Box 2735, Beijing 100080, China
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18
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Wille E, Spiegelhalder FM, Kerner G, Naik D, Trenkwalder A, Hendl G, Schreck F, Grimm R, Tiecke TG, Walraven JTM, Kokkelmans SJJMF, Tiesinga E, Julienne PS. Exploring an ultracold fermi-fermi mixture: interspecies feshbach resonances and scattering properties of 6Li and 40K. PHYSICAL REVIEW LETTERS 2008; 100:053201. [PMID: 18352370 DOI: 10.1103/physrevlett.100.053201] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Indexed: 05/26/2023]
Abstract
We report on the observation of Feshbach resonances in an ultracold mixture of two fermionic species, (6)Li and (40)K. The experimental data are interpreted using a simple asymptotic bound state model and full coupled channels calculations. This unambiguously assigns the observed resonances in terms of various s- and p-wave molecular states and fully characterizes the ground-state scattering properties in any combination of spin states.
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Affiliation(s)
- E Wille
- Institut für Quantenoptik und Quanteninformation, Osterreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
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19
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Iskin M, Sá de Melo CAR. Ultracold heteronuclear molecules and ferroelectric superfluids. PHYSICAL REVIEW LETTERS 2007; 99:110402. [PMID: 17930415 DOI: 10.1103/physrevlett.99.110402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 04/19/2007] [Indexed: 05/25/2023]
Abstract
We analyze the possibility of a ferroelectric transition in heteronuclear molecules consisting of Bose-Bose, Bose-Fermi, or Fermi-Fermi atom pairs. This transition is characterized by the appearance of a spontaneous electric polarization below a critical temperature. We discuss the existence of a ferroelectric Fermi liquid phase for Fermi molecules and the existence of a ferroelectric superfluid phase for Bose molecules characterized by the coexistence of ferroelectric and superfluid orders. Lastly, we propose an experiment to detect ferroelectric correlations through the observation of coherent dipole radiation pulses.
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Affiliation(s)
- M Iskin
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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20
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Dutta O, Kanamoto R, Meystre P. Fermionic stabilization and density-wave ground state of a polar condensate. PHYSICAL REVIEW LETTERS 2007; 99:110404. [PMID: 17930417 DOI: 10.1103/physrevlett.99.110404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Indexed: 05/25/2023]
Abstract
We examine the stability of a trapped dipolar condensate mixed with a single-component fermion gas at T=0. Whereas pure dipolar condensates with a small s-wave interaction are unstable even at small dipole-dipole interaction strength, we find that the admixture of fermions can significantly stabilize them, depending on the strength of the boson-fermion interaction. Within the stable regime we find a region where a ground state is characterized by a density wave along the soft trap direction.
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Affiliation(s)
- O Dutta
- Department of Physics and B2 Institute, The University of Arizona, Tucson, Arizona 85721, USA
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21
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Parish MM, Marchetti FM, Lamacraft A, Simons BD. Polarized Fermi condensates with unequal masses: tuning the tricritical point. PHYSICAL REVIEW LETTERS 2007; 98:160402. [PMID: 17501397 DOI: 10.1103/physrevlett.98.160402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Indexed: 05/15/2023]
Abstract
We consider a two-component atomic Fermi gas within a mean-field, single-channel model, where both the mass and population of each component are unequal. We show that the tricritical point at zero temperature evolves smoothly from the BEC to BCS side of the resonance as a function of mass ratio r. We find that the interior gap state proposed by Liu and Wilczek is always unstable to phase separation, while the breached pair state with one Fermi surface for the excess fermions exhibits differences in its density of states and pair correlation functions depending on which side of the resonance it lies. Finally, we show that, when r greater, similar 3.95, the finite-temperature phase diagram of trapped gases at unitarity becomes topologically distinct from the equal mass system.
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Affiliation(s)
- M M Parish
- Cavendish Laboratory, J. J. Thomson Avenue, Cambridge, CB3 0HE, United Kingdom.
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22
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Papp SB, Wieman CE. Observation of heteronuclear Feshbach molecules from a 85Rb-87Rb gas. PHYSICAL REVIEW LETTERS 2006; 97:180404. [PMID: 17155521 DOI: 10.1103/physrevlett.97.180404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Indexed: 05/12/2023]
Abstract
We report on the observation of ultracold heteronuclear Feshbach molecules. Starting with a 87Rb Bose-Einstein condensate and a cold atomic gas of 85Rb, we utilize previously unobserved interspecies Feshbach resonances to create up to 25,000 molecules. Even though the 85Rb gas is nondegenerate, we observe a large molecular conversion efficiency due to the presence of a quantum degenerate 87Rb gas; this represents a key feature of our system. We compare the molecule creation at two different Feshbach resonances with different magnetic-field widths. The two Feshbach resonances are located at 265.44+/-0.15 G and 372.4+/-1.3 G. We also directly measure the small binding energy of the molecules through resonant magnetic-field association.
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Affiliation(s)
- S B Papp
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA.
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23
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González-Férez R, Mayle M, Schmelcher P. Rovibrational dynamics of LiCs dimers in strong electric fields. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2006.06.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Ospelkaus C, Ospelkaus S, Humbert L, Ernst P, Sengstock K, Bongs K. Ultracold heteronuclear molecules in a 3D optical lattice. PHYSICAL REVIEW LETTERS 2006; 97:120402. [PMID: 17025941 DOI: 10.1103/physrevlett.97.120402] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2006] [Indexed: 05/12/2023]
Abstract
We report on the creation of ultracold heteronuclear molecules assembled from fermionic 40K and bosonic 87Rb atoms in a 3D optical lattice. Molecules are produced at a heteronuclear Feshbach resonance on both the attractive and the repulsive sides of the resonance. We precisely determine the binding energy of the heteronuclear molecules from rf spectroscopy across the Feshbach resonance. We characterize the lifetime of the molecular sample as a function of magnetic field and measure lifetimes between 20 and 120 ms. The efficiency of molecule creation via rf association is measured and is found to decrease as expected for more deeply bound molecules.
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Affiliation(s)
- C Ospelkaus
- Institut für Laserphysik, Luruper Chaussee 149, 22761 Hamburg, Germany
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25
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Ospelkaus S, Ospelkaus C, Humbert L, Sengstock K, Bongs K. Tuning of heteronuclear interactions in a degenerate Fermi-Bose mixture. PHYSICAL REVIEW LETTERS 2006; 97:120403. [PMID: 17025942 DOI: 10.1103/physrevlett.97.120403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Indexed: 05/12/2023]
Abstract
We demonstrate tuning of interactions between fermionic 40K and bosonic 87Rb atoms by Feshbach resonances and access the complete phase diagram of the harmonically trapped mixture from phase separation to collapse. On the attractive side of the resonance, we observe a strongly enhanced mean-field energy of the condensate due to the mutual mean-field confinement, predicted by a Thomas-Fermi model. As we increase heteronuclear interactions beyond a threshold, we observe an induced collapse of the mixture. On the repulsive side of the resonance, we observe vertical phase separation of the mixture in the presence of the gravitational force, thus entering a completely unexplored part of the phase diagram of the mixture. In addition, we identify the 515 G resonance as p wave by its characteristic doublet structure.
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Affiliation(s)
- S Ospelkaus
- Institut für Laserphysik, Luruper Chaussee 149, 22761 Hamburg, Germany
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26
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Barnett R, Petrov D, Lukin M, Demler E. Quantum magnetism with multicomponent dipolar molecules in an optical lattice. PHYSICAL REVIEW LETTERS 2006; 96:190401. [PMID: 16803088 DOI: 10.1103/physrevlett.96.190401] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Indexed: 05/10/2023]
Abstract
We consider bosonic dipolar molecules in an optical lattice prepared in a mixture of different rotational states. The 1/R(3) interaction between molecules for this system is produced by exchanging a quantum of angular momentum between two molecules. We show that the Mott states of such systems have a large variety of quantum phases characterized by dipolar orderings including a state with an ordering wave vector that can be changed by tilting the lattice. As the Mott insulating phase is melted, we also describe several exotic superfluid phases that will occur.
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Affiliation(s)
- Ryan Barnett
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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27
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Snoek M, Haque M, Vandoren S, Stoof HTC. Ultracold superstrings in atomic boson-fermion mixtures. PHYSICAL REVIEW LETTERS 2005; 95:250401. [PMID: 16384435 DOI: 10.1103/physrevlett.95.250401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 08/29/2005] [Indexed: 05/05/2023]
Abstract
We propose a setup with ultracold atomic gases that can be used to make a nonrelativistic superstring in four spacetime dimensions. In particular, we consider for the creation of the superstring a fermionic atomic gas that is trapped in the core of a vortex in a Bose-Einstein condensate. We explain the required tuning of experimental parameters to achieve supersymmetry between the fermionic atoms and the bosonic modes describing the oscillations in the vortex position. Furthermore, we discuss the experimental consequences of supersymmetry.
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Affiliation(s)
- Michiel Snoek
- Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
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28
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Pedri P, Santos L. Two-dimensional bright solitons in dipolar Bose-Einstein condensates. PHYSICAL REVIEW LETTERS 2005; 95:200404. [PMID: 16384040 DOI: 10.1103/physrevlett.95.200404] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Indexed: 05/05/2023]
Abstract
We analyze the physics of bright solitons in 2D dipolar Bose-Einstein condensates. These solitons, which are not possible in short-range interacting gases, constitute the first realistic proposal of fully mobile stable 2D solitons in ultracold gases. In particular, we discuss the necessary conditions for the existence of stable 2D bright solitary waves by means of a 3D analysis of the lowest-lying excitations. We show that the anisotropy of the dipolar potential is crucial, since sufficiently large dipolar interactions can destabilize the 2D soliton. Additionally, we study the scattering of solitary waves, which, contrary to the contact-interacting case, is inelastic and could lead to fusion of the waves. Finally, the experimental possibilities for observability are discussed.
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Affiliation(s)
- P Pedri
- Institut für Theoretische Physik III, Universität Stuttgart, Pfaffenwaldring 57, D-70550, Stuttgart, Germany
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29
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Silber C, Günther S, Marzok C, Deh B, Courteille PW, Zimmermann C. Quantum-degenerate mixture of fermionic lithium and bosonic rubidium gases. PHYSICAL REVIEW LETTERS 2005; 95:170408. [PMID: 16383805 DOI: 10.1103/physrevlett.95.170408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Indexed: 05/05/2023]
Abstract
We report on the observation of sympathetic cooling of a cloud of fermionic 6Li atoms which are thermally coupled to evaporatively cooled bosonic 87Rb. Using this technique we obtain a mixture of quantum-degenerate gases, where the Rb cloud is colder than the critical temperature for Bose-Einstein condensation and the Li cloud is colder than the Fermi temperature. From measurements of the thermalization velocity we estimate the interspecies s-wave triplet scattering length |amx|=20(+9)(-6)aB. We found that the presence of residual rubidium atoms in the |2, 1> and the |1, -1> Zeeman substates gives rise to important losses due to inelastic collisions.
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Affiliation(s)
- C Silber
- Physikalisches Institut, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
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30
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Stuhler J, Griesmaier A, Koch T, Fattori M, Pfau T, Giovanazzi S, Pedri P, Santos L. Observation of dipole-dipole interaction in a degenerate quantum gas. PHYSICAL REVIEW LETTERS 2005; 95:150406. [PMID: 16241705 DOI: 10.1103/physrevlett.95.150406] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Indexed: 05/05/2023]
Abstract
We have investigated the expansion of a Bose-Einstein condensate of strongly magnetic chromium atoms. The long-range and anisotropic magnetic dipole-dipole interaction leads to an anisotropic deformation of the expanding chromium condensate which depends on the orientation of the atomic dipole moments. Our measurements are consistent with the theory of dipolar quantum gases and show that a chromium condensate is an excellent model system to study dipolar interactions in such gases.
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Affiliation(s)
- J Stuhler
- 5. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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31
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Dickerscheid DBM, van Oosten D, Tillema EJ, Stoof HTC. Quantum phases in a resonantly interacting boson-fermion mixture. PHYSICAL REVIEW LETTERS 2005; 94:230404. [PMID: 16090448 DOI: 10.1103/physrevlett.94.230404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Indexed: 05/03/2023]
Abstract
We consider a resonantly interacting boson-fermion mixture of 40K and 87Rb atoms in an optical lattice. We show that by using a red-detuned optical lattice the mixture can be accurately described by a generalized Hubbard model for 40K and 87Rb atoms, and 40K-87Rb molecules. The microscopic parameters of this model are fully determined by the details of the optical lattice and the interspecies Feshbach resonance in the absence of the lattice. We predict a quantum phase transition to occur in this system already at low atomic filling fraction, and present the phase diagram as a function of the temperature and the applied magnetic field.
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Affiliation(s)
- D B M Dickerscheid
- Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
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32
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Cvitas MT, Soldán P, Hutson JM, Honvault P, Launay JM. Ultracold collisions involving heteronuclear alkali metal dimers. PHYSICAL REVIEW LETTERS 2005; 94:200402. [PMID: 16090228 DOI: 10.1103/physrevlett.94.200402] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Indexed: 05/03/2023]
Abstract
We carry out the first quantum dynamics calculations on ultracold atom-diatom collisions in isotopic mixtures. The systems studied are spin-polarized 7Li + 6Li7Li, 7Li + 6Li2, 6Li + 6Li7Li, and 6Li + 7Li2. Reactive scattering can occur for the first two systems even when the molecules are in their ground rovibrational states, but is slower than vibrational relaxation in homonuclear systems. Implications for sympathetic cooling of heteronuclear molecules are discussed.
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Affiliation(s)
- Marko T Cvitas
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom
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33
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Sage JM, Sainis S, Bergeman T, DeMille D. Optical production of ultracold polar molecules. PHYSICAL REVIEW LETTERS 2005; 94:203001. [PMID: 16090241 DOI: 10.1103/physrevlett.94.203001] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Indexed: 05/03/2023]
Abstract
We demonstrate the production of ultracold polar RbCs molecules in their vibronic ground state, via photoassociation of laser-cooled atoms followed by a laser-stimulated state transfer process. The resulting sample of X1Sigma+ (nu = 0) molecules has a translational temperature of approximately 100 microK and a narrow distribution of rotational states. With the method described here it should be possible to produce samples even colder in all degrees of freedom, as well as other bialkali species.
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Affiliation(s)
- Jeremy M Sage
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
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34
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Koch CP, Masnou-Seeuws F, Kosloff R. Creating ground state molecules with optical feshbach resonances in tight traps. PHYSICAL REVIEW LETTERS 2005; 94:193001. [PMID: 16090168 DOI: 10.1103/physrevlett.94.193001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Indexed: 05/03/2023]
Abstract
We propose to create ultracold ground state molecules in an atomic Bose-Einstein condensate by adiabatic crossing of an optical Feshbach resonance. We envision a scheme where the laser intensity and possibly also frequency are linearly ramped over the resonance. Our calculations for (87)Rb show that for sufficiently tight traps it is possible to avoid spontaneous emission while retaining adiabaticity, and conversion efficiencies of up to 50% can be expected.
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35
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Werner J, Griesmaier A, Hensler S, Stuhler J, Pfau T, Simoni A, Tiesinga E. Observation of Feshbach resonances in an ultracold gas of 52Cr. PHYSICAL REVIEW LETTERS 2005; 94:183201. [PMID: 15904366 DOI: 10.1103/physrevlett.94.183201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Indexed: 05/02/2023]
Abstract
We have observed Feshbach resonances in collisions between ultracold 52Cr atoms. This is the first observation of collisional Feshbach resonances in an atomic species with more than one valence electron. The zero nuclear spin of 52Cr and thus the absence of a Fermi-contact interaction leads to regularly spaced resonance sequences. By comparing resonance positions with multichannel scattering calculations we determine the s-wave scattering length of the lowest (2S+1)Sigma(+)(g) potentials to be 112(14) a(0), 58(6) a(0), and -7(20) a(0) for S=6, 4, and 2, respectively, where a(0)=0.0529 nm.
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Affiliation(s)
- J Werner
- 5 Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany
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36
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Wang D, Qi J, Stone MF, Nikolayeva O, Wang H, Hattaway B, Gensemer SD, Gould PL, Eyler EE, Stwalley WC. Photoassociative production and trapping of ultracold KRb molecules. PHYSICAL REVIEW LETTERS 2004; 93:243005. [PMID: 15697805 DOI: 10.1103/physrevlett.93.243005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Indexed: 05/24/2023]
Abstract
We have produced ultracold heteronuclear KRb molecules by the process of photoassociation in a two-species magneto-optical trap. Following decay of the photoassociated KRb*, the molecules are detected using two-photon ionization and time-of-flight mass spectroscopy of KRb+. A portion of the metastable triplet molecules thus formed are magnetically trapped. Photoassociative spectra down to 91 cm(-1) below the K(4s)+Rb(5p(1/2)) asymptote have been obtained. We have made assignments to all eight of the attractive Hund's case (c) KRb* potential curves in this spectral region.
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Affiliation(s)
- D Wang
- Physics Department, University of Connecticut, Storrs, CT 06269, USA
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37
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Inouye S, Goldwin J, Olsen ML, Ticknor C, Bohn JL, Jin DS. Observation of heteronuclear Feshbach resonances in a mixture of bosons and fermions. PHYSICAL REVIEW LETTERS 2004; 93:183201. [PMID: 15525160 DOI: 10.1103/physrevlett.93.183201] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Indexed: 05/24/2023]
Abstract
Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic 87Rb and fermionic 40K atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and 543+/-2 G. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet cross-species scattering lengths, yielding (-281+/-15)a(0) and (-54+/-12)a(0), respectively. The width of the loss feature at 543 G is 3.7+/-1.5 G wide; this broad Feshbach resonance should enable experimental control of the interspecies interactions.
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Affiliation(s)
- S Inouye
- JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, CO 80309, USA
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