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Cominotti R, Berti A, Farolfi A, Zenesini A, Lamporesi G, Carusotto I, Recati A, Ferrari G. Observation of Massless and Massive Collective Excitations with Faraday Patterns in a Two-Component Superfluid. Phys Rev Lett 2022; 128:210401. [PMID: 35687467 DOI: 10.1103/physrevlett.128.210401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/28/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
We report on the experimental measurement of the dispersion relation of the density and spin collective excitation modes in an elongated two-component superfluid of ultracold bosonic atoms. Our parametric spectroscopic technique is based on the external modulation of the transverse confinement frequency, leading to the formation of density and spin Faraday waves. We show that the application of a coherent coupling between the two components reduces the phase symmetry and gives a finite mass to the spin modes.
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Affiliation(s)
- R Cominotti
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Berti
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Farolfi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Zenesini
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Lamporesi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - I Carusotto
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Recati
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Ferrari
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
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2
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Chanda T, Lewenstein M, Zakrzewski J, Tagliacozzo L. Phase Diagram of 1+1D Abelian-Higgs Model and Its Critical Point. Phys Rev Lett 2022; 128:090601. [PMID: 35302796 DOI: 10.1103/physrevlett.128.090601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
We determine the phase diagram of the Abelian-Higgs model in one spatial dimension and time (1+1D) on a lattice. We identify a line of first order phase transitions separating the Higgs region from the confined one. This line terminates in a quantum critical point above which the two regions are connected by a smooth crossover. We analyze the critical point and find compelling evidence for its description as the product of two noninteracting systems: a massless free fermion and a massless free boson. However, we find also some surprising results that cannot be explained by our simple picture, suggesting this newly discovered critical point is an unusual one.
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Affiliation(s)
- Titas Chanda
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34151 Trieste, Italy
- Instytut Fizyki Teoretycznej, Uniwersytet Jagielloński, Łojasiewicza 11, 30-348 Kraków, Poland
| | - Maciej Lewenstein
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Avenue Carl Friedrich Gauss 3, 08860 Barcelona, Spain
- ICREA, Passeig Lluis Companys 23, 08010 Barcelona, Spain
| | - Jakub Zakrzewski
- Instytut Fizyki Teoretycznej, Uniwersytet Jagielloński, Łojasiewicza 11, 30-348 Kraków, Poland
- Mark Kac Complex Systems Research Center, Jagiellonian University in Krakow, Łojasiewicza 11, 30-348 Kraków, Poland
| | - Luca Tagliacozzo
- Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113b, Madrid 28006, Spain
- Departament de Física Quàntica i Astrofísica and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
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3
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Jin S, Zhang W, Guo X, Chen X, Zhou X, Li X. Evidence of Potts-Nematic Superfluidity in a Hexagonal sp^{2} Optical Lattice. Phys Rev Lett 2021; 126:035301. [PMID: 33543961 DOI: 10.1103/physrevlett.126.035301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/29/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
As in between liquid and crystal phases lies a nematic liquid crystal, which breaks rotation with preservation of translation symmetry, there is a nematic superfluid phase bridging a superfluid and a supersolid. The nematic order also emerges in interacting electrons and has been found to largely intertwine with multiorbital correlation in high-temperature superconductivity, where Ising nematicity arises from a four-fold rotation symmetry C_{4} broken down to C_{2}. Here, we report an observation of a three-state (Z_{3}) quantum nematic order, dubbed "Potts-nematicity", in a system of cold atoms loaded in an excited band of a hexagonal optical lattice described by an sp^{2}-orbital hybridized model. This Potts-nematic quantum state spontaneously breaks a three-fold rotation symmetry of the lattice, qualitatively distinct from the Ising nematicity. Our field theory analysis shows that the Potts-nematic order is stabilized by intricate renormalization effects enabled by strong interorbital mixing present in the hexagonal lattice. This discovery paves a way to investigate quantum vestigial orders in multiorbital atomic superfluids.
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Affiliation(s)
- Shengjie Jin
- State Key Laboratory of Advanced Optical Communication System and Network, Department of Electronics, Peking University, Beijing 100871, China
| | - Wenjun Zhang
- State Key Laboratory of Advanced Optical Communication System and Network, Department of Electronics, Peking University, Beijing 100871, China
| | - Xinxin Guo
- State Key Laboratory of Advanced Optical Communication System and Network, Department of Electronics, Peking University, Beijing 100871, China
| | - Xuzong Chen
- State Key Laboratory of Advanced Optical Communication System and Network, Department of Electronics, Peking University, Beijing 100871, China
| | - Xiaoji Zhou
- State Key Laboratory of Advanced Optical Communication System and Network, Department of Electronics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Xiaopeng Li
- State Key Laboratory of Surface Physics, Institute of Nanoelectronics and Quantum Computing, Department of Physics, Fudan University, Shanghai 200438, China
- Shanghai Qizhi Institute, AI Tower, Xuhui District, Shanghai 200232, China
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4
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Kato S, Inaba K, Sugawa S, Shibata K, Yamamoto R, Yamashita M, Takahashi Y. Laser spectroscopic probing of coexisting superfluid and insulating states of an atomic Bose-Hubbard system. Nat Commun 2016; 7:11341. [PMID: 27094083 PMCID: PMC4843003 DOI: 10.1038/ncomms11341] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/16/2016] [Indexed: 11/23/2022] Open
Abstract
A system of ultracold atoms in an optical lattice has been regarded as an ideal quantum simulator for a Hubbard model with extremely high controllability of the system parameters. While making use of the controllability, a comprehensive measurement across the weakly to strongly interacting regimes in the Hubbard model to discuss the quantum many-body state is still limited. Here we observe a great change in the excitation energy spectra across the two regimes in an atomic Bose–Hubbard system by using a spectroscopic technique, which can resolve the site occupancy in the lattice. By quantitatively comparing the observed spectra and numerical simulations based on sum rule relations and a binary fluid treatment under a finite temperature Gutzwiller approximation, we show that the spectra reflect the coexistence of a delocalized superfluid state and a localized insulating state across the two regimes. A system of ultracold atoms in an optical lattice can be used as a quantum simulator for the Hubbard model with high controllability. Here, the authors report a laser spectroscopy study of an ytterbium ultracold bosonic gas across the weakly to strongly interacting regime.
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Affiliation(s)
- Shinya Kato
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kensuke Inaba
- NTT Basic Research Laboratories, NTT Corporation, Atsugi 243-0198, Japan
| | - Seiji Sugawa
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kosuke Shibata
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Ryuta Yamamoto
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Makoto Yamashita
- NTT Basic Research Laboratories, NTT Corporation, Atsugi 243-0198, Japan
| | - Yoshiro Takahashi
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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5
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Bukov M, Gopalakrishnan S, Knap M, Demler E. Prethermal Floquet Steady States and Instabilities in the Periodically Driven, Weakly Interacting Bose-Hubbard Model. Phys Rev Lett 2015; 115:205301. [PMID: 26613449 DOI: 10.1103/physrevlett.115.205301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Indexed: 06/05/2023]
Abstract
We explore prethermal Floquet steady states and instabilities of the weakly interacting two-dimensional Bose-Hubbard model subject to periodic driving. We develop a description of the nonequilibrium dynamics, at arbitrary drive strength and frequency, using a weak-coupling conserving approximation. We establish the regimes in which conventional (zero-momentum) and unconventional [(π,π)-momentum] condensates are stable on intermediate time scales. We find that condensate stability is enhanced by increasing the drive strength, because this decreases the bandwidth of quasiparticle excitations and thus impedes resonant absorption and heating. Our results are directly relevant to a number of current experiments with ultracold bosons.
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Affiliation(s)
- Marin Bukov
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA
| | - Sarang Gopalakrishnan
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Michael Knap
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
- Physics Department, Walter Schottky Institute, and Institute for Advanced Study, Technical University Munich, 85748 Garching, Germany
| | - Eugene Demler
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
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6
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Hai K, Luo Y, Lu G, Hai W. Phase-controlled localization and directed transport in an optical bipartite lattice. Opt Express 2014; 22:4277-4289. [PMID: 24663751 DOI: 10.1364/oe.22.004277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate coherent control of a single atom interacting with an optical bipartite lattice via a combined high-frequency modulation. Our analytical results show that the quantum tunneling and dynamical localization can depend on phase difference between the modulation components, which leads to a different route for the coherent destruction of tunneling and a convenient phase-control method for stabilizing the system to implement the directed transport of atom. The similar directed transport and the phase-controlled quantum transition are revealed for the corresponding many-particle system. The results can be referable for experimentally manipulating quantum transport and transition of cold atoms in the tilted and shaken optical bipartite lattice or of analogical optical two-mode quantum beam splitter, and also can be extended to other optical and solid-state systems.
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7
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Jaskula JC, Partridge GB, Bonneau M, Lopes R, Ruaudel J, Boiron D, Westbrook CI. Acoustic analog to the dynamical Casimir effect in a Bose-Einstein condensate. Phys Rev Lett 2012; 109:220401. [PMID: 23368107 DOI: 10.1103/physrevlett.109.220401] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Indexed: 06/01/2023]
Abstract
We have modulated the density of a trapped Bose-Einstein condensate by changing the trap stiffness, thereby modulating the speed of sound. We observe the creation of correlated excitations with equal and opposite momenta, and show that for a well-defined modulation frequency, the frequency of the excitations is half that of the trap modulation frequency.
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Affiliation(s)
- J-C Jaskula
- Laboratoire Charles Fabry, Institut d'Optique, CNRS, Université Paris-Sud, 2 avenue Augustin Fresnel, 91127 Palaiseau, France
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8
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Endres M, Fukuhara T, Pekker D, Cheneau M, Schauβ P, Gross C, Demler E, Kuhr S, Bloch I. The ‘Higgs’ amplitude mode at the two-dimensional superfluid/Mott insulator transition. Nature 2012; 487:454-8. [DOI: 10.1038/nature11255] [Citation(s) in RCA: 241] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 05/16/2012] [Indexed: 11/10/2022]
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9
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Chen YA, Nascimbène S, Aidelsburger M, Atala M, Trotzky S, Bloch I. Controlling correlated tunneling and superexchange interactions with ac-driven optical lattices. Phys Rev Lett 2011; 107:210405. [PMID: 22181863 DOI: 10.1103/physrevlett.107.210405] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Indexed: 05/31/2023]
Abstract
The dynamical control of tunneling processes of single particles plays a major role in science ranging from Shapiro steps in Josephson junctions to the control of chemical reactions via light in molecules. Here we show how such control can be extended to the regime of correlated tunneling of strongly interacting particles. Through a periodic modulation of a biased tunnel contact, we have been able to coherently control single-particle and correlated two-particle hopping processes. We have furthermore been able to extend this control to superexchange spin interactions in the presence of a magnetic-field gradient. Such photon-assisted superexchange processes constitute a novel approach to realize arbitrary XXZ spin models in ultracold quantum gases, where transverse and Ising-type spin couplings can be fully controlled in magnitude and sign.
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Affiliation(s)
- Yu-Ao Chen
- Fakultät für Physik, Ludwig-Maximilians-Universität, München, Germany.
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10
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Bissbort U, Götze S, Li Y, Heinze J, Krauser JS, Weinberg M, Becker C, Sengstock K, Hofstetter W. Detecting the amplitude mode of strongly interacting lattice bosons by Bragg scattering. Phys Rev Lett 2011; 106:205303. [PMID: 21668240 DOI: 10.1103/physrevlett.106.205303] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Indexed: 05/30/2023]
Abstract
We report the first detection of the Higgs-type amplitude mode using Bragg spectroscopy in a strongly interacting condensate of ultracold atoms in an optical lattice. By the comparison of our experimental data with a spatially resolved, time-dependent bosonic Gutzwiller calculation, we obtain good quantitative agreement. This allows for a clear identification of the amplitude mode, showing that it can be detected with full momentum resolution by going beyond the linear response regime. A systematic shift of the sound and amplitude modes' resonance frequencies due to the finite Bragg beam intensity is observed.
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Affiliation(s)
- Ulf Bissbort
- Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, 60438 Frankfurt/Main, Germany
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11
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Tokuno A, Giamarchi T. Spectroscopy for cold atom gases in periodically phase-modulated optical lattices. Phys Rev Lett 2011; 106:205301. [PMID: 21668238 DOI: 10.1103/physrevlett.106.205301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 04/04/2011] [Indexed: 05/30/2023]
Abstract
The response of cold atom gases to small periodic phase modulation of an optical lattice is discussed. For bosonic gases, the energy absorption rate is given, within linear response theory, by the imaginary part of the current autocorrelation function. For fermionic gases in a strong lattice potential, the same correlation function can be probed via the production rate of double occupancy. The phase modulation gives thus direct access to the conductivity of the system, as a function of the modulation frequency. We give an example of application in the case of bosonic systems at zero temperature and discuss the link between the phase and amplitude modulation.
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Affiliation(s)
- Akiyuki Tokuno
- DPMC-MaNEP, University of Geneva, 24 Quai Ernest-Ansermet CH-1211 Geneva, Switzerland
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12
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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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13
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Huber SD, Theiler B, Altman E, Blatter G. Amplitude mode in the quantum phase model. Phys Rev Lett 2008; 100:050404. [PMID: 18352348 DOI: 10.1103/physrevlett.100.050404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 12/11/2007] [Indexed: 05/26/2023]
Abstract
We derive the collective low-energy excitations of the quantum phase model of interacting lattice bosons within the superfluid state using a dynamical variational approach. We recover the well-known sound (or Goldstone) mode and derive a gapped (Higgs-type) mode that was overlooked in previous studies of the quantum phase model. This mode is relevant to ultracold atoms in a strong optical lattice potential. We predict the signature of the gapped mode in lattice modulation experiments and show how it evolves with increasing interaction strength.
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Affiliation(s)
- S D Huber
- Theoretische Physik, ETH Zurich, CH-8093 Zurich, Switzerland
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14
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Abstract
Coherence properties of Bose-Einstein condensates offer the potential for improved interferometric phase contrast. However, decoherence effects due to the mean-field interaction shorten the coherence time, thus limiting potential sensitivity. In this work, we demonstrate increased coherence times with number squeezed states in an optical lattice using the decay of Bloch oscillations to probe the coherence time. We extend coherence times by a factor of 2 over those expected with coherent state Bose-Einstein condensate interferometry. We observe quantitative agreement with theory both for the degree of initial number squeezing as well as for prolonged coherence times.
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Affiliation(s)
- Wei Li
- Physics Department, Stanford University, Stanford, California 94305, USA
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15
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Abstract
We investigate the phase diagram of spinless bosons with long range (variant 1/r(3)) repulsive interactions, relevant to ultracold polarized atoms or molecules, using density matrix renormalization group. Between the two conventional insulating phases, the Mott and density wave phases, we find a new phase possessing hidden order revealed by nonlocal string correlations analogous to those characterizing the Haldane gapped phase of integer spin chains. We develop a mean field theory that describes the low-energy excitations in all three insulating phases. This is used to calculate the absorption spectrum due to oscillatory lattice modulation. We predict a sharp resonance in the spectrum due to a collective excitation of the new phase that would provide clear evidence for the existence of this phase.
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Affiliation(s)
- Emanuele G Dalla Torre
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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16
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Chin JK, Miller DE, Liu Y, Stan C, Setiawan W, Sanner C, Xu K, Ketterle W. Evidence for superfluidity of ultracold fermions in an optical lattice. Nature 2006; 443:961-4. [PMID: 17066028 DOI: 10.1038/nature05224] [Citation(s) in RCA: 305] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 08/25/2006] [Indexed: 11/08/2022]
Abstract
The study of superfluid fermion pairs in a periodic potential has important ramifications for understanding superconductivity in crystalline materials. By using cold atomic gases, various models of condensed matter can be studied in a highly controllable environment. Weakly repulsive fermions in an optical lattice could undergo d-wave pairing at low temperatures, a possible mechanism for high temperature superconductivity in the copper oxides. The lattice potential could also strongly increase the critical temperature for s-wave superfluidity. Recent experimental advances in bulk atomic gases include the observation of fermion-pair condensates and high-temperature superfluidity. Experiments with fermions and bosonic bound pairs in optical lattices have been reported but have not yet addressed superfluid behaviour. Here we report the observation of distinct interference peaks when a condensate of fermionic atom pairs is released from an optical lattice, implying long-range order (a property of a superfluid). Conceptually, this means that s-wave pairing and coherence of fermion pairs have now been established in a lattice potential, in which the transport of atoms occurs by quantum mechanical tunnelling and not by simple propagation. These observations were made for interactions on both sides of a Feshbach resonance. For larger lattice depths, the coherence was lost in a reversible manner, possibly as a result of a transition from superfluid to insulator. Such strongly interacting fermions in an optical lattice can be used to study a new class of hamiltonians with interband and atom-molecule couplings.
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Affiliation(s)
- J K Chin
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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17
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Snoek M, Haque M, Vandoren S, Stoof HTC. Ultracold superstrings in atomic boson-fermion mixtures. Phys Rev Lett 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] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Gerbier F, Widera A, Fölling S, Mandel O, Gericke T, Bloch I. Phase coherence of an atomic Mott insulator. Phys Rev Lett 2005; 95:050404. [PMID: 16090855 DOI: 10.1103/physrevlett.95.050404] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Indexed: 05/03/2023]
Abstract
We investigate the phase coherence properties of ultracold Bose gases in optical lattices, with special emphasis on the Mott insulating phase. We show that phase coherence on short length scales persists even deep in the insulating phase, preserving a finite visibility of the interference pattern observed after free expansion. This behavior can be attributed to a coherent admixture of particle-hole pairs to the perfect Mott state for small but finite tunneling. In addition, small but reproducible kinks are seen in the visibility, in a broad range of atom numbers. We interpret them as signatures for density redistribution in the shell structure of the trapped Mott insulator.
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Affiliation(s)
- Fabrice Gerbier
- Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz, Germany
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19
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Dickerscheid DBM, van Oosten D, Tillema EJ, Stoof HTC. Quantum phases in a resonantly interacting boson-fermion mixture. Phys Rev Lett 2005; 94:230404. [PMID: 16090448 DOI: 10.1103/physrevlett.94.230404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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