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He C, Nie X, Avalos V, Botsi S, Kumar S, Yang A, Dieckmann K. Efficient Creation of Ultracold Ground State ^{6}Li^{40}K Polar Molecules. PHYSICAL REVIEW LETTERS 2024; 132:243401. [PMID: 38949353 DOI: 10.1103/physrevlett.132.243401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 01/26/2024] [Accepted: 05/09/2024] [Indexed: 07/02/2024]
Abstract
We report the creation of ultracold ground state ^{6}Li^{40}K polar molecules with high efficiency. Starting from weakly bound molecules, stimulated Raman adiabatic passage is adopted to coherently transfer the molecules to their singlet rovibrational ground state |X^{1}Σ^{+},v=0,J=0⟩. By employing a singlet stimulated Raman adiabatic passage pathway and low-phase-noise narrow-linewidth lasers, we observed a one-way transfer efficiency of 96(4)%. Held in an optical dipole trap, the lifetime of the ground state molecules is measured to be 5.0(3) ms. The large permanent dipole moment of LiK is confirmed by applying a dc electric field on the molecules and performing Stark shift spectroscopy of the ground state. With recent advances in the quantum control of collisions, our work paves the way for exploring quantum many-body physics with strongly interacting ^{6}Li^{40}K molecules.
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2
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Zhao B, Pan JW. Quantum control of reactions and collisions at ultralow temperatures. Chem Soc Rev 2022; 51:1685-1701. [PMID: 35169822 DOI: 10.1039/d1cs01040a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
At temperatures close to absolute zero, the molecular reactions and collisions are dominantly governed by quantum mechanics. Remarkable quantum phenomena such as quantum tunneling, quantum threshold behavior, quantum resonances, quantum interference, and quantum statistics are expected to be the main features in ultracold reactions and collisions. Ultracold molecules offer great opportunities and challenges in the study of these intriguing quantum phenomena in molecular processes. In this article, we review the recent progress in the preparation of ultracold molecules and the study of ultracold reactions and collisions using ultracold molecules. We focus on the controlled ultracold chemistry and the scattering resonances at ultralow temperatures. The challenges in understanding the complex ultracold reactions and collisions are also discussed.
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Affiliation(s)
- Bo Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. .,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. .,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
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3
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Yang H, Wang XY, Su Z, Cao J, Zhang DC, Rui J, Zhao B, Bai CL, Pan JW. Evidence for the association of triatomic molecules in ultracold 23Na 40K + 40K mixtures. Nature 2022; 602:229-233. [PMID: 35140383 DOI: 10.1038/s41586-021-04297-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 11/29/2021] [Indexed: 11/09/2022]
Abstract
Ultracold assembly of diatomic molecules has enabled great advances in controlled chemistry, ultracold chemical physics and quantum simulation with molecules1-3. Extending the ultracold association to triatomic molecules will offer many new research opportunities and challenges in these fields. A possible approach is to form triatomic molecules in a mixture of ultracold atoms and diatomic molecules by using a Feshbach resonance between them4,5. Although ultracold atom-diatomic-molecule Feshbach resonances have been observed recently6,7, using these resonances to form triatomic molecules remains challenging. Here we report on evidence of the association of triatomic molecules near the Feshbach resonance between 23Na40K molecules in the rovibrational ground state and 40K atoms. We apply a radio-frequency pulse to drive the free-bound transition in ultracold mixtures of 23Na40K and 40K and monitor the loss of 23Na40K molecules. The association of triatomic molecules manifests itself as an additional loss feature in the radio-frequency spectra, which can be distinguished from the atomic loss feature. The observation that the distance between the association feature and the atomic transition changes with the magnetic field provides strong evidence for the formation of triatomic molecules. The binding energy of the triatomic molecules is estimated from the measurements. Our work contributes to the understanding of the complex ultracold atom-molecule Feshbach resonances and may open up an avenue towards the preparation and control of ultracold triatomic molecules.
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Affiliation(s)
- Huan Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China.,Shanghai Research Center for Quantum Sciences, Shanghai, China
| | - Xin-Yao Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China.,Shanghai Research Center for Quantum Sciences, Shanghai, China.,Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhen Su
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China.,Shanghai Research Center for Quantum Sciences, Shanghai, China
| | - Jin Cao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China.,Shanghai Research Center for Quantum Sciences, Shanghai, China
| | - De-Chao Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China.,Shanghai Research Center for Quantum Sciences, Shanghai, China
| | - Jun Rui
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China.,Shanghai Research Center for Quantum Sciences, Shanghai, China
| | - Bo Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China. .,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China. .,Shanghai Research Center for Quantum Sciences, Shanghai, China.
| | - Chun-Li Bai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China. .,University of Chinese Academy of Sciences, Beijing, China.
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China. .,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China. .,Shanghai Research Center for Quantum Sciences, Shanghai, China.
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4
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Steely A, Myers RL, Kortyna A, Huennekens J, Malenda RF, Faust C. Fitting an experimental potential energy curve for the 10(0 +)[43Π0] electronic state of NaCs. J Chem Phys 2019; 151:024307. [DOI: 10.1063/1.5100748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrew Steely
- Department of Physics, Susquehanna University, 514 University Ave., Selinsgrove, Pennsylvania 17870, USA
| | - Rachel L. Myers
- Department of Physics and Earth Science, Moravian College, 1200 Main St., Bethlehem, Pennsylvania 18018, USA
| | - Andrew Kortyna
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, USA
| | - John Huennekens
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USA
| | - R. F. Malenda
- Department of Physics and Earth Science, Moravian College, 1200 Main St., Bethlehem, Pennsylvania 18018, USA
| | - Carl Faust
- Department of Physics, Susquehanna University, 514 University Ave., Selinsgrove, Pennsylvania 17870, USA
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5
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Thomas R, Chilcott M, Tiesinga E, Deb AB, Kjærgaard N. Observation of bound state self-interaction in a nano-eV atom collider. Nat Commun 2018; 9:4895. [PMID: 30459426 PMCID: PMC6243998 DOI: 10.1038/s41467-018-07375-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/25/2018] [Indexed: 12/03/2022] Open
Abstract
Quantum mechanical scattering resonances for colliding particles occur when a continuum scattering state couples to a discrete bound state between them. The coupling also causes the bound state to interact with itself via the continuum and leads to a shift in the bound state energy, but, lacking knowledge of the bare bound state energy, measuring this self-energy via the resonance position has remained elusive. Here, we report on the direct observation of self-interaction by using a nano-eV atom collider to track the position of a magnetically-tunable Feshbach resonance through a parameter space spanned by energy and magnetic field. Our system of potassium and rubidium atoms displays a strongly non-monotonic resonance trajectory with an exceptionally large self-interaction energy arising from an interplay between the Feshbach bound state and a different, virtual bound state at a fixed energy near threshold. Self-interaction of a bound state through its coupling to the continuum is a phenomenon that is very difficult to observe. Here, the authors optically collide atomic clouds of rubidium and potassium to observe the self-interaction energy through precise measurements of magnetically tunable Feshbach resonances.
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Affiliation(s)
- Ryan Thomas
- Department of Physics, QSO-Centre for Quantum Science, and Dodd-Walls Centre for Photonic and Quantum Technologies, University of Otago, 730 Cumberland Street, Dunedin 9016, New Zealand
| | - Matthew Chilcott
- Department of Physics, QSO-Centre for Quantum Science, and Dodd-Walls Centre for Photonic and Quantum Technologies, University of Otago, 730 Cumberland Street, Dunedin 9016, New Zealand
| | - Eite Tiesinga
- Joint Quantum Institute and Centre for Quantum Information and Computer Science, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899, USA
| | - Amita B Deb
- Department of Physics, QSO-Centre for Quantum Science, and Dodd-Walls Centre for Photonic and Quantum Technologies, University of Otago, 730 Cumberland Street, Dunedin 9016, New Zealand
| | - Niels Kjærgaard
- Department of Physics, QSO-Centre for Quantum Science, and Dodd-Walls Centre for Photonic and Quantum Technologies, University of Otago, 730 Cumberland Street, Dunedin 9016, New Zealand.
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6
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Dutta O, Gajda M, Hauke P, Lewenstein M, Lühmann DS, Malomed BA, Sowiński T, Zakrzewski J. Non-standard Hubbard models in optical lattices: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2015; 78:066001. [PMID: 26023844 DOI: 10.1088/0034-4885/78/6/066001] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Originally, the Hubbard model was derived for describing the behavior of strongly correlated electrons in solids. However, for over a decade now, variations of it have also routinely been implemented with ultracold atoms in optical lattices, allowing their study in a clean, essentially defect-free environment. Here, we review some of the vast literature on this subject, with a focus on more recent non-standard forms of the Hubbard model. After giving an introduction to standard (fermionic and bosonic) Hubbard models, we discuss briefly common models for mixtures, as well as the so-called extended Bose-Hubbard models, that include interactions between neighboring sites, next-neighbor sites, and so on. The main part of the review discusses the importance of additional terms appearing when refining the tight-binding approximation for the original physical Hamiltonian. Even when restricting the models to the lowest Bloch band is justified, the standard approach neglects the density-induced tunneling (which has the same origin as the usual on-site interaction). The importance of these contributions is discussed for both contact and dipolar interactions. For sufficiently strong interactions, the effects related to higher Bloch bands also become important even for deep optical lattices. Different approaches that aim at incorporating these effects, mainly via dressing the basis, Wannier functions with interactions, leading to effective, density-dependent Hubbard-type models, are reviewed. We discuss also examples of Hubbard-like models that explicitly involve higher p orbitals, as well as models that dynamically couple spin and orbital degrees of freedom. Finally, we review mean-field nonlinear Schrödinger models of the Salerno type that share with the non-standard Hubbard models nonlinear coupling between the adjacent sites. In that part, discrete solitons are the main subject of consideration. We conclude by listing some open problems, to be addressed in the future.
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Affiliation(s)
- Omjyoti Dutta
- Instytut Fizyki imienia Mariana Smoluchowskiego, Uniwersytet Jagielloński, Łojasiewicza 11, 30-348 Kraków, Poland
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7
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Two-component dipolar Bose-Einstein condensate in concentrically coupled annular traps. Sci Rep 2015; 5:8684. [PMID: 25731962 PMCID: PMC4346789 DOI: 10.1038/srep08684] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/29/2015] [Indexed: 11/30/2022] Open
Abstract
Dipolar Bosonic atoms confined in external potentials open up new avenues for quantum-state manipulation and will contribute to the design and exploration of novel functional materials. Here we investigate the ground-state and rotational properties of a rotating two-component dipolar Bose-Einstein condensate, which consists of both dipolar bosonic atoms with magnetic dipole moments aligned vertically to the condensate and one without dipole moments, confined in concentrically coupled annular traps. For the nonrotational case, it is found that the tunable dipolar interaction can be used to control the location of each component between the inner and outer rings, and to induce the desired ground-state phase. Under finite rotation, it is shown that there exists a critical value of rotational frequency for the nondipolar case, above which vortex state can form at the trap center, and the related vortex structures depend strongly on the rotational frequency. For the dipolar case, it is found that various ground-state phases and the related vortex structures, such as polygonal vortex clusters and vortex necklaces, can be obtained via a proper choice of the dipolar interaction and rotational frequency. Finally, we also study and discuss the formation process of such vortex structures.
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Ma J, Li Y, Wu J, Xiao L, Jia S. Laser intensity induced transparency in atom-molecular transition process. CHINESE SCIENCE BULLETIN-CHINESE 2014. [DOI: 10.1007/s11434-014-0448-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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9
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Armaitis J, Duine RA, Stoof HTC. Quantum rotor model for a Bose-Einstein condensate of dipolar molecules. PHYSICAL REVIEW LETTERS 2013; 111:215301. [PMID: 24313496 DOI: 10.1103/physrevlett.111.215301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/02/2013] [Indexed: 06/02/2023]
Abstract
We show that a Bose-Einstein condensate of heteronuclear molecules in the regime of small and static electric fields is described by a quantum rotor model for the macroscopic electric dipole moment of the molecular gas cloud. We solve this model exactly and find the symmetric, i.e., rotationally invariant, and dipolar phases expected from the single-molecule problem, but also an axial and planar nematic phase due to many-body effects. Investigation of the wave function of the macroscopic dipole moment also reveals squeezing of the probability distribution for the angular momentum of the molecules.
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Affiliation(s)
- J Armaitis
- Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
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10
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Wenz AN, Zurn G, Murmann S, Brouzos I, Lompe T, Jochim S. From Few to Many: Observing the Formation of a Fermi Sea One Atom at a Time. Science 2013; 342:457-60. [DOI: 10.1126/science.1240516] [Citation(s) in RCA: 232] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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11
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Windpassinger P, Sengstock K. Engineering novel optical lattices. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2013; 76:086401. [PMID: 23828639 DOI: 10.1088/0034-4885/76/8/086401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Optical lattices have developed into a widely used and highly recognized tool to study many-body quantum physics with special relevance for solid state type systems. One of the most prominent reasons for this success is the high degree of tunability in the experimental setups. While at the beginning quasi-static, cubic geometries were mainly explored, the focus of the field has now shifted toward new lattice topologies and the dynamical control of lattice structures. In this review we intend to give an overview of the progress recently achieved in this field on the experimental side. In addition, we discuss theoretical proposals exploiting specifically these novel lattice geometries.
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Affiliation(s)
- Patrick Windpassinger
- Institut für Laserphysik and Zentrum für Optische Quantentechnologien, Universität Hamburg, Hamburg, Germany.
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12
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Herrera F, Madison KW, Krems RV, Berciu M. Investigating polaron transitions with polar molecules. PHYSICAL REVIEW LETTERS 2013; 110:223002. [PMID: 23767718 DOI: 10.1103/physrevlett.110.223002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Indexed: 06/02/2023]
Abstract
We determine the phase diagram of a polaron model with mixed breathing-mode and Su-Schrieffer-Heeger couplings and show that it has two sharp transitions, in contrast to pure models which exhibit one (for Su-Schrieffer-Heeger coupling) or no (for breathing-mode coupling) transition. We then show that ultracold molecules trapped in optical lattices can be used as a quantum simulator to study precisely this mixed Hamiltonian, and that the relative contributions of the two couplings can be tuned with external electric fields. The parameters of current experiments place them in the region where one of the transitions occurs. We also propose a scheme to measure the polaron dispersion using stimulated Raman spectroscopy.
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Affiliation(s)
- Felipe Herrera
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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13
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Sala S, Zürn G, Lompe T, Wenz AN, Murmann S, Serwane F, Jochim S, Saenz A. Coherent molecule formation in anharmonic potentials near confinement-induced resonances. PHYSICAL REVIEW LETTERS 2013; 110:203202. [PMID: 25167405 DOI: 10.1103/physrevlett.110.203202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Indexed: 06/03/2023]
Abstract
We perform a theoretical and experimental study of a system of two ultracold atoms with tunable interaction in an elongated trapping potential. We show that the coupling of center-of-mass and relative motion due to an anharmonicity of the trapping potential leads to a coherent coupling of a state of an unbound atom pair and a molecule with a center of mass excitation. By performing the experiment with exactly two particles we exclude three-body losses and can therefore directly observe coherent molecule formation. We find quantitative agreement between our theory of inelastic confinement-induced resonances and the experimental results. This shows that the effects of center-of-mass to relative-motion coupling can have a significant impact on the physics of quantum systems near center-of-mass to relative-motion coupling resonances.
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Affiliation(s)
- S Sala
- AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany
| | - G Zürn
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - T Lompe
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291 Darmstadt, Germany
| | - A N Wenz
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - S Murmann
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - F Serwane
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291 Darmstadt, Germany
| | - S Jochim
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291 Darmstadt, Germany
| | - A Saenz
- AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany
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14
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Bertaina G, Fratini E, Giorgini S, Pieri P. Quantum Monte Carlo study of a resonant Bose-Fermi mixture. PHYSICAL REVIEW LETTERS 2013; 110:115303. [PMID: 25166551 DOI: 10.1103/physrevlett.110.115303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Indexed: 06/03/2023]
Abstract
We study a resonant Bose-Fermi mixture at zero temperature by using the fixed-node diffusion Monte Carlo method. We explore the system from weak to strong boson-fermion interaction, for different concentrations of the bosons relative to the fermion component. We focus on the case where the boson density n(B) is smaller than the fermion density n(F), for which a first-order quantum phase transition is found from a state with condensed bosons immersed in a Fermi sea, to a Fermi-Fermi mixture of composite fermions and unpaired fermions. We obtain the equation of state and the phase diagram, and we find that the region of phase separation shrinks to zero for vanishing n(B).
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Affiliation(s)
- G Bertaina
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne EPFL, CH-1015 Lausanne, Switzerland
| | - E Fratini
- School of Science and Technology, Physics Division, University of Camerino and CNISM, I-62032 Camerino, Italy
| | - S Giorgini
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - P Pieri
- School of Science and Technology, Physics Division, University of Camerino and CNISM, I-62032 Camerino, Italy and INFN, Sezione di Perugia, Perugia, Italy
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15
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Wu CH, Park JW, Ahmadi P, Will S, Zwierlein MW. Ultracold fermionic Feshbach molecules of 23Na40K. PHYSICAL REVIEW LETTERS 2012; 109:085301. [PMID: 23002753 DOI: 10.1103/physrevlett.109.085301] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Indexed: 06/01/2023]
Abstract
We report on the formation of ultracold weakly bound Feshbach molecules of 23Na40K, the first fermionic molecule that is chemically stable in its absolute ground state. The lifetime of the nearly degenerate molecular gas exceeds 100 ms in the vicinity of the Feshbach resonance. The measured dependence of the molecular binding energy on the magnetic field demonstrates the open-channel character of the molecules over a wide field range and implies significant singlet admixture. This will enable efficient transfer into the singlet vibrational ground state, resulting in a stable molecular Fermi gas with strong dipolar interactions.
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Affiliation(s)
- Cheng-Hsun Wu
- MIT-Harvard Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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16
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Armstrong JR, Zinner NT, Fedorov DV, Jensen AS. Virial expansion coefficients in the harmonic approximation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:021115. [PMID: 23005730 DOI: 10.1103/physreve.86.021115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 06/29/2012] [Indexed: 06/01/2023]
Abstract
The virial expansion method is applied within a harmonic approximation to an interacting N-body system of identical fermions. We compute the canonical partition functions for two and three particles to get the two lowest orders in the expansion. The energy spectrum is carefully interpolated to reproduce ground-state properties at low temperature and the noninteracting high-temperature limit of constant virial coefficients. This resembles the smearing of shell effects in finite systems with increasing temperature. Numerical results are discussed for the second and third virial coefficients as functions of dimension, temperature, interaction, and transition temperature between low- and high-energy limits.
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Affiliation(s)
- J R Armstrong
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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Affiliation(s)
- Christiane P. Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Strasse 40,
34132 Kassel, Germany
| | - Moshe Shapiro
- Department
of Chemistry, University of British Columbia, Vancouver, Canada V6T
1Z1, and Department of Chemical Physics, The Weizmann Institute, Rehovot, Israel 76100
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18
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Chotia A, Neyenhuis B, Moses SA, Yan B, Covey JP, Foss-Feig M, Rey AM, Jin DS, Ye J. Long-lived dipolar molecules and Feshbach molecules in a 3D optical lattice. PHYSICAL REVIEW LETTERS 2012; 108:080405. [PMID: 22463505 DOI: 10.1103/physrevlett.108.080405] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Indexed: 05/31/2023]
Abstract
We have realized long-lived ground-state polar molecules in a 3D optical lattice, with a lifetime of up to 25 s, which is limited only by off-resonant scattering of the trapping light. Starting from a 2D optical lattice, we observe that the lifetime increases dramatically as a small lattice potential is added along the tube-shaped lattice traps. The 3D optical lattice also dramatically increases the lifetime for weakly bound Feshbach molecules. For a pure gas of Feshbach molecules, we observe a lifetime of greater than 20 s in a 3D optical lattice; this represents a 100-fold improvement over previous results. This lifetime is also limited by off-resonant scattering, the rate of which is related to the size of the Feshbach molecule. Individually trapped Feshbach molecules in the 3D lattice can be converted to pairs of K and Rb atoms and back with nearly 100% efficiency.
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Affiliation(s)
- Amodsen Chotia
- JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
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19
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Zürn G, Serwane F, Lompe T, Wenz AN, Ries MG, Bohn JE, Jochim S. Fermionization of two distinguishable fermions. PHYSICAL REVIEW LETTERS 2012; 108:075303. [PMID: 22401221 DOI: 10.1103/physrevlett.108.075303] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Indexed: 05/31/2023]
Abstract
We study a system of two distinguishable fermions in a 1D harmonic potential. This system has the exceptional property that there is an analytic solution for arbitrary values of the interparticle interaction. We tune the interaction strength and compare the measured properties of the system to the theoretical prediction. For diverging interaction strength, the energy and square modulus of the wave function for two distinguishable particles are the same as for a system of two noninteracting identical fermions. This is referred to as fermionization. We have observed this phenomenon by directly comparing two distinguishable fermions with diverging interaction strength with two identical fermions in the same potential. We observe good agreement between experiment and theory. By adding more particles our system can be used as a quantum simulator for more complex systems where no theoretical solution is available.
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Affiliation(s)
- G Zürn
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Germany.
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20
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Armstrong JR, Zinner NT, Fedorov DV, Jensen AS. Quantum statistics and thermodynamics in the harmonic approximation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:021117. [PMID: 22463163 DOI: 10.1103/physreve.85.021117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Indexed: 05/31/2023]
Abstract
We describe a method to compute thermodynamic quantities in the harmonic approximation for identical bosons and fermions in an external confining field. We use the canonical partition function where only energies and their degeneracies enter. The number of states of given energy and symmetry is found by separating the center-of-mass motion, and by counting the remaining states of given symmetry and excitation energy of the relative motion. The oscillator frequencies that enter the harmonic Hamiltonian can be derived from realistic model parameters, and the method corresponds to an effective interaction approach based on harmonic interactions. To demonstrate the method, we apply it to systems in two dimensions. Numerical calculations are compared to a brute force method, which is considerably more computationally intensive.
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Affiliation(s)
- J R Armstrong
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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21
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Hanna TM, Tiesinga E, Mitchell WF, Julienne PS. Resonant control of polar molecules in individual sites of an optical lattice. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2012; 85:022703. [PMID: 28919699 PMCID: PMC5600210 DOI: 10.1103/physreva.85.022703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We study the resonant control of two nonreactive polar molecules in an optical lattice site, focusing on the example of RbCs. Collisional control can be achieved by tuning bound states of the intermolecular dipolar potential by varying the applied electric field or trap frequency. We consider a wide range of electric fields and trapping geometries, showing that a three-dimensional optical lattice allows significantly wider avoided crossings than free space or quasi-two dimensional geometries. Furthermore, we find that dipolar confinement-induced resonances can be created with reasonable trapping frequencies and electric fields, and have widths that will enable useful control in forthcoming experiments.
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Affiliation(s)
- Thomas M Hanna
- Joint Quantum Institute, National Institute of Standards and Technology, and University of Maryland, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423, USA
| | - Eite Tiesinga
- Joint Quantum Institute, National Institute of Standards and Technology, and University of Maryland, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423, USA
| | - William F Mitchell
- Applied and Computational Mathematics Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8910, Gaithersburg, Maryland 20899-8910, USA
| | - Paul S Julienne
- Joint Quantum Institute, National Institute of Standards and Technology, and University of Maryland, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423, USA
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22
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Ultrafast Manipulation of Raman Transitions and Prevention of Decoherence Using Chirped Pulses and Optical Frequency Combs. ADVANCES IN QUANTUM CHEMISTRY 2012. [DOI: 10.1016/b978-0-12-396498-4.00007-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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23
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Snoek M, Titvinidze I, Bloch I, Hofstetter W. Effect of interactions on harmonically confined Bose-Fermi mixtures in optical lattices. PHYSICAL REVIEW LETTERS 2011; 106:155301. [PMID: 21568569 DOI: 10.1103/physrevlett.106.155301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Indexed: 05/30/2023]
Abstract
We investigate a Bose-Fermi mixture in a three-dimensional optical lattice, trapped in a harmonic potential. Using generalized dynamical mean-field theory, which treats the Bose-Bose and Bose-Fermi interaction in a fully nonperturbative way, we show that for experimentally relevant parameters a peak in the condensate fraction close to the point of vanishing Bose-Fermi interaction is reproduced within a single-band framework. We identify two physical mechanisms contributing to this effect: the spatial redistribution of particles when the interspecies interaction is changed and the reduced phase space for strong interactions, which results in a higher temperature at fixed entropy.
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Affiliation(s)
- Michiel Snoek
- Institute for Theoretical Physics, University of Amsterdam, 1090 GL Amsterdam, The Netherlands
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24
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Fröhlich B, Feld M, Vogt E, Koschorreck M, Zwerger W, Köhl M. Radio-frequency spectroscopy of a strongly interacting two-dimensional Fermi gas. PHYSICAL REVIEW LETTERS 2011; 106:105301. [PMID: 21469798 DOI: 10.1103/physrevlett.106.105301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/13/2011] [Indexed: 05/30/2023]
Abstract
We realize and study a strongly interacting two-component atomic Fermi gas confined to two dimensions in an optical lattice. Using radio-frequency spectroscopy we measure the interaction energy of the strongly interacting gas. We observe the confinement-induced Feshbach resonance on the attractive side of the 3D Feshbach resonance and find the existence of confinement-induced molecules in very good agreement with theoretical predictions.
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Affiliation(s)
- Bernd Fröhlich
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB30HE, United Kingdom
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25
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Cremon JC, Bruun GM, Reimann SM. Tunable Wigner states with dipolar atoms and molecules. PHYSICAL REVIEW LETTERS 2010; 105:255301. [PMID: 21231598 DOI: 10.1103/physrevlett.105.255301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 09/15/2010] [Indexed: 05/30/2023]
Abstract
We study the few-body physics of trapped atoms or molecules with electric or magnetic dipole moments aligned by an external field. Using exact numerical diagonalization appropriate for the strongly correlated regime, as well as a classical analysis, we show how Wigner localization emerges with increasing coupling strength. The Wigner states exhibit nontrivial geometries due to the anisotropy of the interaction. This leads to transitions between different Wigner states as the tilt angle of the dipoles with the confining plane is changed. Intriguingly, while the individual Wigner states are well described by a classical analysis, the transitions between different Wigner states are strongly affected by quantum statistics. This can be understood by considering the interplay between quantum-mechanical and spatial symmetry properties. Finally, we demonstrate that our results are relevant to experimentally realistic systems.
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Affiliation(s)
- J C Cremon
- Mathematical Physics, LTH, Lund University, SE-22100 Lund, Sweden
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26
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Cui X, Wang Y, Zhou F. Resonance scattering in optical lattices and molecules: interband versus intraband effects. PHYSICAL REVIEW LETTERS 2010; 104:153201. [PMID: 20481984 DOI: 10.1103/physrevlett.104.153201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Indexed: 05/29/2023]
Abstract
We study the low-energy two-body scattering in optical lattices with higher-band effects included in an effective potential, using a renormalization group approach. The approach captures the most dominating higher-band effects as well as all multiple scattering processes in the lowest band. For an arbitrary negative free space scattering length (a(s)), a resonance of low-energy scattering occurs as the lattice potential depths reach a critical value v(c); these resonances, with continuously tunable positions v(c) and widths W, can be mainly driven either by intraband or both intra- and interband effects depending on the magnitude of a(s). We have also studied the scattering amplitudes and the formation of molecules when interband effects are dominating, and discussed an intimate relation between molecules for negative a(s) and repulsively bound states pioneered by Winkler et al. [Nature (London) 441, 853 (2006)].
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Affiliation(s)
- Xiaoling Cui
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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27
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Ospelkaus S, Ni KK, Quéméner G, Neyenhuis B, Wang D, de Miranda MHG, Bohn JL, Ye J, Jin DS. Controlling the hyperfine state of rovibronic ground-state polar molecules. PHYSICAL REVIEW LETTERS 2010; 104:030402. [PMID: 20366634 DOI: 10.1103/physrevlett.104.030402] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 11/12/2009] [Indexed: 05/29/2023]
Abstract
We report the preparation of a rovibronic ground-state molecular quantum gas in a single hyperfine state and, in particular, the absolute lowest quantum state. This addresses the last internal degree of freedom remaining after the recent production of a near quantum degenerate gas of molecules in their rovibronic ground state, and provides a crucial step towards full control over molecular quantum gases. We demonstrate a scheme that is general for bialkali polar molecules and allows the preparation of molecules in a single hyperfine state or in an arbitrary coherent superposition of hyperfine states. The scheme relies on electric-dipole, two-photon microwave transitions through rotationally excited states and makes use of electric nuclear quadrupole interactions to transfer molecular population between different hyperfine states.
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Affiliation(s)
- S Ospelkaus
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
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28
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Danshita I, Sá de Melo CAR. Stability of superfluid and supersolid phases of dipolar bosons in optical lattices. PHYSICAL REVIEW LETTERS 2009; 103:225301. [PMID: 20366103 DOI: 10.1103/physrevlett.103.225301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 11/03/2009] [Indexed: 05/29/2023]
Abstract
We perform a stability analysis of superfluid (SF) and supersolid (SS) phases of polarized dipolar bosons in two-dimensional optical lattices at high filling factors and zero temperature, and obtain the phase boundaries between SF, checkerboard SS (CSS), striped SS (SSS), and collapse. We show that the phase diagram can be explored through the application of an external field and the tuning of its direction with respect to the optical lattice plane. In particular, we find a transition between the CSS and SSS phases.
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Affiliation(s)
- Ippei Danshita
- Department of Physics, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan
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29
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Maeda K, Baym G, Hatsuda T. Simulating dense QCD matter with ultracold atomic boson-fermion mixtures. PHYSICAL REVIEW LETTERS 2009; 103:085301. [PMID: 19792735 DOI: 10.1103/physrevlett.103.085301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 06/09/2009] [Indexed: 05/28/2023]
Abstract
We delineate, as an analog of two-flavor dense quark matter, the phase structure of a many-body mixture of atomic bosons and fermions in two internal states with a tunable boson-fermion attraction. The bosons b correspond to diquarks, and the fermions f to unpaired quarks. For weak b-f attraction, the system is a mixture of a Bose-Einstein condensate and degenerate fermions, while for strong attraction composite b-f fermions N, analogs of the nucleon, are formed, which are superfluid due to the N-N attraction in the spin-singlet channel. We determine the symmetry breaking patterns at finite temperature as a function of the b-f coupling strength, and relate the phase diagram to that of dense QCD.
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Affiliation(s)
- Kenji Maeda
- Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
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30
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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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31
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32
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Voigt AC, Taglieber M, Costa L, Aoki T, Wieser W, Hänsch TW, Dieckmann K. Ultracold heteronuclear fermi-fermi molecules. PHYSICAL REVIEW LETTERS 2009; 102:020405. [PMID: 19257253 DOI: 10.1103/physrevlett.102.020405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Indexed: 05/27/2023]
Abstract
We report on the first creation of ultracold bosonic heteronuclear molecules of two fermionic species, 6Li and 40K, by a magnetic field sweep across an interspecies s-wave Feshbach resonance. This allows us to associate up to 4x10(4) molecules with high efficiencies of up to 50%. Using direct imaging of the molecules, we measure increased lifetimes of the molecules close to resonance of more than 100 ms in the molecule-atom mixture stored in a harmonic trap.
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Affiliation(s)
- A-C Voigt
- Department für Physik der Ludwig-Maximilians-Universität, Schellingstrasse 4, 80799 Munich, Germany.
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33
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Ospelkaus S, Ni KK, de Miranda MHG, Neyenhuis B, Wang D, Kotochigova S, Julienne PS, Jin DS, Ye J. Ultracold polar molecules near quantum degeneracy. Faraday Discuss 2009; 142:351-9; discussion 429-61. [DOI: 10.1039/b821298h] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Julienne PS. Ultracold molecules from ultracold atoms: a case study with the KRb molecule. Faraday Discuss 2009; 142:361-88; discussion 429-61. [DOI: 10.1039/b820917k] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Ni KK, Ospelkaus S, Nesbitt DJ, Ye J, Jin DS. A dipolar gas of ultracold molecules. Phys Chem Chem Phys 2009; 11:9626-39. [DOI: 10.1039/b911779b] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Ni KK, Ospelkaus S, de Miranda MHG, Pe'er A, Neyenhuis B, Zirbel JJ, Kotochigova S, Julienne PS, Jin DS, Ye J. A High Phase-Space-Density Gas of Polar Molecules. Science 2008; 322:231-5. [DOI: 10.1126/science.1163861] [Citation(s) in RCA: 1446] [Impact Index Per Article: 90.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- K.-K. Ni
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - S. Ospelkaus
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - M. H. G. de Miranda
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - A. Pe'er
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - B. Neyenhuis
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - J. J. Zirbel
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - S. Kotochigova
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - P. S. Julienne
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - D. S. Jin
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
| | - J. Ye
- JILA, National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309–0440, USA
- Physics Department, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute, NIST, and University of Maryland, Gaithersburg, MD 20899–8423, USA
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37
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Jing H, Cheng J, Meystre P. Quantum noise in the collective abstraction reaction A + B2-->AB + B. PHYSICAL REVIEW LETTERS 2008; 101:073603. [PMID: 18764534 DOI: 10.1103/physrevlett.101.073603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Indexed: 05/26/2023]
Abstract
We demonstrate theoretically that the collective abstraction reaction A + B2-->AB + B can be realized efficiently with degenerate bosonic or fermionic matter waves. We show that this is dominated by quantum fluctuations, which are critical in triggering its initial stages with the appearance of macroscopic nonclassical correlations of the atomic and molecular fields as a result. This study opens up a promising new regime of quantum-degenerate matter-wave chemistry.
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Affiliation(s)
- H Jing
- B2 Institute and Department of Physics, The University of Arizona, Tucson, Arizona 85721, USA
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38
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Papp SB, Pino JM, Wieman CE. Tunable miscibility in a dual-species Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2008; 101:040402. [PMID: 18764310 DOI: 10.1103/physrevlett.101.040402] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Indexed: 05/26/2023]
Abstract
We report on the observation of controllable phase separation in a dual-species Bose-Einstein condensate with 85Rb and 87Rb. Interatomic interactions between the different components determine the miscibility of the two quantum fluids. In our experiments, we can clearly observe immiscible behavior via a dramatic spatial separation of the two species. Furthermore, a magnetic-field Feshbach resonance is used to change them between miscible and immiscible by tuning the 85Rb scattering length. The spatial density pattern of the immiscible quantum fluids exhibits complex alternating-domain structures that are uncharacteristic of its stationary ground state.
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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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39
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Klawunn M, Nath R, Pedri P, Santos L. Transverse instability of straight vortex lines in dipolar Bose-Einstein condensates. PHYSICAL REVIEW LETTERS 2008; 100:240403. [PMID: 18643556 DOI: 10.1103/physrevlett.100.240403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Indexed: 05/26/2023]
Abstract
The physics of vortex lines in dipolar condensates is studied. Because of the nonlocality of the dipolar interaction, the 3D character of the vortex plays a more important role in dipolar gases than in typical short-range interacting ones. In particular, the dipolar interaction significantly affects the stability of the transverse modes of the vortex line. Remarkably, in the presence of a periodic potential along the vortexline, the spectrum of transverse modes shows a rotonlike minimum, which eventually destabilizes the straight vortex when the BEC as a whole is still stable, opening the possibility for new scenarios for vortex-line configurations in dipolar gases.
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Affiliation(s)
- M Klawunn
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstr. 2, D-30167, Hannover, Germany
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40
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Hudson ER, Gilfoy NB, Kotochigova S, Sage JM, DeMille D. Inelastic collisions of ultracold heteronuclear molecules in an optical trap. PHYSICAL REVIEW LETTERS 2008; 100:203201. [PMID: 18518530 DOI: 10.1103/physrevlett.100.203201] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Indexed: 05/26/2023]
Abstract
Ultracold RbCs molecules in high-lying vibrational levels of the a3Sigma+ ground electronic state are confined in an optical trap. Inelastic collision rates of these molecules with both Rb and Cs atoms are determined for individual vibrational levels, across an order of magnitude of binding energies. The long-range dispersion coefficients for the collision process are calculated and used in a model that accurately reproduce the observed scattering rates.
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Affiliation(s)
- Eric R Hudson
- Department of Physics, Yale University, 217 Prospect Street, New Haven, Connecticut 06511, USA.
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41
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Marcelis B, Verhaar B, Kokkelmans S. Total control over ultracold interactions via electric and magnetic fields. PHYSICAL REVIEW LETTERS 2008; 100:153201. [PMID: 18518105 DOI: 10.1103/physrevlett.100.153201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Indexed: 05/26/2023]
Abstract
The scattering length is commonly used to characterize the strength of ultracold atomic interactions, since it is the leading parameter in the low-energy expansion of the scattering phase shift. Its value can be modified via a magnetic field, by using a Feshbach resonance. However, the effective range term, which is the second parameter in the phase shift expansion, determines the width of the resonance and gives rise to important properties of ultracold gases. Independent control over this parameter is not possible by using a magnetic field only. We demonstrate that a combination of magnetic and electric fields can be used to get independent control over both parameters, which leads to full control over elastic ultracold interactions.
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Affiliation(s)
- Bout Marcelis
- Eindhoven University of Technology, Eindhoven, The Netherlands
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42
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Zirbel JJ, Ni KK, Ospelkaus S, D'Incao JP, Wieman CE, Ye J, Jin DS. Collisional stability of fermionic Feshbach molecules. PHYSICAL REVIEW LETTERS 2008; 100:143201. [PMID: 18518030 DOI: 10.1103/physrevlett.100.143201] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Indexed: 05/26/2023]
Abstract
Using a Feshbach resonance, we create ultracold fermionic molecules starting from a Bose-Fermi atom gas mixture. The resulting mixture of atoms and weakly bound molecules provides a rich system for studying few-body collisions because of the variety of atomic collision partners for molecules; either bosonic, fermionic, or distinguishable atoms. Inelastic loss of the molecules near the Feshbach resonance is dramatically affected by the quantum statistics of the colliding particles and the scattering length. In particular, we observe a molecule lifetime as long as 100 ms near the Feshbach resonance.
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Affiliation(s)
- J J Zirbel
- JILA, Quantum Physics Division, National Institute of Standards and Technology and the Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
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43
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Tikhonenkov I, Malomed BA, Vardi A. Anisotropic solitons in dipolar bose-einstein condensates. PHYSICAL REVIEW LETTERS 2008; 100:090406. [PMID: 18352684 DOI: 10.1103/physrevlett.100.090406] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Indexed: 05/26/2023]
Abstract
Starting with a Gaussian variational ansatz, we predict anisotropic bright solitons in quasi-2D Bose-Einstein condensates consisting of atoms with dipole moments polarized perpendicular to the confinement direction. Unlike isotropic solitons predicted for the moments aligned with the confinement axis [Phys. Rev. Lett. 95, 200404 (2005)10.1103/PhysRevLett.95.200404], no sign reversal of the dipole-dipole interaction is necessary to support the solitons. Direct 3D simulations confirm their stability.
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Affiliation(s)
- I Tikhonenkov
- Department of Chemistry, Ben-Gurion University of the Negev, POB. 653, Beer-Sheva 84105, Israel
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44
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Sinha S, Santos L. Cold dipolar gases in quasi-one-dimensional geometries. PHYSICAL REVIEW LETTERS 2007; 99:140406. [PMID: 17930653 DOI: 10.1103/physrevlett.99.140406] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Indexed: 05/25/2023]
Abstract
We analyze the physics of cold dipolar gases in quasi-one-dimensional geometries, showing that the confinement-induced scattering resonances produced by the transversal trapping are crucially affected by the dipole-dipole interaction. As a consequence, the dipolar interaction may drastically change the properties of quasi-1D dipolar condensates, even for situations in which the dipolar interaction would be completely overwhelmed by the short-range interactions in a 3D environment.
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Affiliation(s)
- S Sinha
- S N Bose National Centre for Basic Sciences, Block JD, Sector III, Kolkata, India
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45
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Petrov DS, Astrakharchik GE, Papoular DJ, Salomon C, Shlyapnikov GV. Crystalline phase of strongly interacting fermi mixtures. PHYSICAL REVIEW LETTERS 2007; 99:130407. [PMID: 17930564 DOI: 10.1103/physrevlett.99.130407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2007] [Indexed: 05/25/2023]
Abstract
We show that the system of weakly bound molecules of heavy and light fermionic atoms is characterized by a long-range intermolecular repulsion and can undergo a gas-crystal quantum transition if the mass ratio exceeds a critical value. For the critical mass ratio above 100 obtained in our calculations, this crystalline order can be observed as a superlattice in an optical lattice for heavy atoms with a small filling factor. We also find that this novel system is sufficiently stable with respect to molecular relaxation into deep bound states and to the process of trimer formation.
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Affiliation(s)
- D S Petrov
- Laboratoire de Physique Théorique et Modèles Statistiques, CNRS, Université Paris Sud, 91405 Orsay, France
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46
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Jing H, Cheng J, Meystre P. Coherent atom-trimer conversion in a repulsive Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2007; 99:133002. [PMID: 17930584 DOI: 10.1103/physrevlett.99.133002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Indexed: 05/25/2023]
Abstract
We show that the use of a generalized atom-molecule dark state permits the enhanced coherent creation of triatomic molecules in a repulsive atomic Bose-Einstein condensate, with further enhancement being possible in the case of heteronuclear trimers via the constructive interference between two chemical reaction channels.
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Affiliation(s)
- H Jing
- B2 Institute and Department of Physics, The University of Arizona, Tucson, Arizona 85721, USA
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47
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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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48
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Hemmerich A, Morais Smith C. Excitation of a d-Density wave in an optical lattice with driven tunneling. PHYSICAL REVIEW LETTERS 2007; 99:113002. [PMID: 17930433 DOI: 10.1103/physrevlett.99.113002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Indexed: 05/25/2023]
Abstract
Quantum phases with unusual symmetries may play a key role in the understanding of solid state systems at low temperatures. We propose a realistic scenario, well in reach of present experimental techniques, which should permit us to produce a stationary quantum state with d x2-y2 symmetry in a two-dimensional bosonic optical square lattice. This state, characterized by alternating rotational flux in each plaquette, arises from driven tunneling implemented by a stimulated Raman scattering process. We discuss bosons in a square lattice; however, more complex systems involving other lattice geometries appear possible.
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Affiliation(s)
- A Hemmerich
- Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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49
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Kotochigova S. Prospects for making polar molecules with microwave fields. PHYSICAL REVIEW LETTERS 2007; 99:073003. [PMID: 17930893 DOI: 10.1103/physrevlett.99.073003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Indexed: 05/25/2023]
Abstract
We propose a mechanism to produce ultracold polar molecules with microwave fields. It converts trapped ultracold atoms into vibrationally excited molecules by a single microwave transition and entirely depends on the existence of a permanent dipole moment in the molecules. As opposed to production of molecules by photoassociation or magnetic-field Feshbach resonances, our method does not rely on properties of excited states or existence of Feshbach resonances. We determine conditions for optimal creation of polar molecules in vibrationally excited states of the ground-state potential by changing frequency and intensity of the microwave field. We also explore the possibility to produce vibrationally cold molecules by combining the microwave field with an optical Raman transition or by applying a microwave field to Feshbach molecules. The production mechanism is illustrated for KRb and RbCs.
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Affiliation(s)
- Svetlana Kotochigova
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122-6082, USA
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50
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Lahaye T, Koch T, Fröhlich B, Fattori M, Metz J, Griesmaier A, Giovanazzi S, Pfau T. Strong dipolar effects in a quantum ferrofluid. Nature 2007; 448:672-5. [PMID: 17687319 DOI: 10.1038/nature06036] [Citation(s) in RCA: 412] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Accepted: 06/15/2007] [Indexed: 11/08/2022]
Abstract
Symmetry-breaking interactions have a crucial role in many areas of physics, ranging from classical ferrofluids to superfluid (3)He and d-wave superconductivity. For superfluid quantum gases, a variety of new physical phenomena arising from the symmetry-breaking interaction between electric or magnetic dipoles are expected. Novel quantum phases in optical lattices, such as chequerboard or supersolid phases, are predicted for dipolar bosons. Dipolar interactions can also enrich considerably the physics of quantum gases with internal degrees of freedom. Arrays of dipolar particles could be used for efficient quantum information processing. Here we report the realization of a chromium Bose-Einstein condensate with strong dipolar interactions. By using a Feshbach resonance, we reduce the usual isotropic contact interaction, such that the anisotropic magnetic dipole-dipole interaction between 52Cr atoms becomes comparable in strength. This induces a change of the aspect ratio of the atom cloud; for strong dipolar interactions, the inversion of ellipticity during expansion (the usual 'smoking gun' evidence for a Bose-Einstein condensate) can be suppressed. These effects are accounted for by taking into account the dipolar interaction in the superfluid hydrodynamic equations governing the dynamics of the gas, in the same way as classical ferrofluids can be described by including dipolar terms in the classical hydrodynamic equations. Our results are a first step in the exploration of the unique properties of quantum ferrofluids.
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Affiliation(s)
- Thierry Lahaye
- 5. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
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