1
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Lagoin C, Baldwin K, Pfeiffer L, Dubin F. Superlattice Quantum Solid of Dipolar Excitons. PHYSICAL REVIEW LETTERS 2024; 132:176001. [PMID: 38728707 DOI: 10.1103/physrevlett.132.176001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/01/2024] [Indexed: 05/12/2024]
Abstract
We study dipolar excitons confined at 330 mK in a square electrostatic lattice of a GaAs double quantum well. In the dipolar occupation blockade regime, at 3/2 filling, we evidence that excitons form a face-centered superlattice quantum solid. This phase is realized with high purity across 36 lattice sites, in a regime where the mean interaction energy exceeds the depth of the electrostatic lattice confinement. The superlattice solid then closely relates to Wigner crystals.
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Affiliation(s)
- Camille Lagoin
- CRHEA, CNRS and Université Côte d'Azur, Valbonne, France
- Institut des Nanosciences de Paris, CNRS and Sorbonne Université, Paris, France
| | - Kirk Baldwin
- PRISM, Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey, USA
| | - Loren Pfeiffer
- PRISM, Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey, USA
| | - François Dubin
- CRHEA, CNRS and Université Côte d'Azur, Valbonne, France
- Institut des Nanosciences de Paris, CNRS and Sorbonne Université, Paris, France
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2
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Di Carli A, Parsonage C, La Rooij A, Koehn L, Ulm C, Duncan CW, Daley AJ, Haller E, Kuhr S. Commensurate and incommensurate 1D interacting quantum systems. Nat Commun 2024; 15:474. [PMID: 38212298 PMCID: PMC10784295 DOI: 10.1038/s41467-023-44610-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/19/2023] [Indexed: 01/13/2024] Open
Abstract
Single-atom imaging resolution of many-body quantum systems in optical lattices is routinely achieved with quantum-gas microscopes. Key to their great versatility as quantum simulators is the ability to use engineered light potentials at the microscopic level. Here, we employ dynamically varying microscopic light potentials in a quantum-gas microscope to study commensurate and incommensurate 1D systems of interacting bosonic Rb atoms. Such incommensurate systems are analogous to doped insulating states that exhibit atom transport and compressibility. Initially, a commensurate system with unit filling and fixed atom number is prepared between two potential barriers. We deterministically create an incommensurate system by dynamically changing the position of the barriers such that the number of available lattice sites is reduced while retaining the atom number. Our systems are characterised by measuring the distribution of particles and holes as a function of the lattice filling, and interaction strength, and we probe the particle mobility by applying a bias potential. Our work provides the foundation for preparation of low-entropy states with controlled filling in optical-lattice experiments.
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Affiliation(s)
- Andrea Di Carli
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Christopher Parsonage
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Arthur La Rooij
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Lennart Koehn
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Clemens Ulm
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Callum W Duncan
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Andrew J Daley
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Elmar Haller
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom
| | - Stefan Kuhr
- Department of Physics, SUPA, University of Strathclyde, Glasgow, G4 0NG, United Kingdom.
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3
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Ciardi M, Angelone A, Mezzacapo F, Cinti F. Quasicrystalline Bose Glass in the Absence of Disorder and Quasidisorder. PHYSICAL REVIEW LETTERS 2023; 131:173402. [PMID: 37955480 DOI: 10.1103/physrevlett.131.173402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 09/05/2023] [Accepted: 10/03/2023] [Indexed: 11/14/2023]
Abstract
We study the low-temperature phases of interacting bosons on a two-dimensional quasicrystalline lattice. By means of numerically exact path integral Monte Carlo simulations, we show that for sufficiently weak interactions the system is a homogeneous Bose-Einstein condensate that develops density modulations for increasing filling factor. The simultaneous occurrence of sizeable condensate fraction and density modulation can be interpreted as the analogous, in a quasicrystalline lattice, of supersolid phases occurring in conventional periodic lattices. For sufficiently large interaction strength and particle density, global condensation is lost and quantum exchanges are restricted to specific spatial regions. The emerging quantum phase is therefore a Bose glass, which here is stabilized in the absence of any source of disorder or quasidisorder, purely as a result of the interplay between quantum effects, particle interactions and quasicrystalline substrate. This finding clearly indicates that (quasi)disorder is not essential to observe Bose glass physics. Our results are of interest for ongoing experiments on (quasi)disorder-free quasicrystalline lattices.
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Affiliation(s)
- Matteo Ciardi
- Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019, Sesto Fiorentino (FI), Italy
- INFN, Sezione di Firenze, I-50019, Sesto Fiorentino (FI), Italy
| | - Adriano Angelone
- Sorbonne Université, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC, F-75005 Paris, France
- eXact lab s.r.l., Via Francesco Crispi 56-34126 Trieste, Italy
| | - Fabio Mezzacapo
- Univ Lyon, Ens de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - Fabio Cinti
- Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019, Sesto Fiorentino (FI), Italy
- INFN, Sezione di Firenze, I-50019, Sesto Fiorentino (FI), Italy
- Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
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4
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Zhu Z, Yao H, Sanchez-Palencia L. Thermodynamic Phase Diagram of Two-Dimensional Bosons in a Quasicrystal Potential. PHYSICAL REVIEW LETTERS 2023; 130:220402. [PMID: 37327407 DOI: 10.1103/physrevlett.130.220402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 05/10/2023] [Indexed: 06/18/2023]
Abstract
Quantum simulation of quasicrystals in synthetic bosonic matter now paves the way for the exploration of these intriguing systems in wide parameter ranges. Yet thermal fluctuations in such systems compete with quantum coherence and significantly affect the zero-temperature quantum phases. Here we determine the thermodynamic phase diagram of interacting bosons in a two-dimensional, homogeneous quasicrystal potential. We find our results using quantum Monte Carlo simulations. Finite-size effects are carefully taken into account and the quantum phases are systematically distinguished from thermal phases. In particular, we demonstrate stabilization of a genuine Bose glass phase against the normal fluid in sizable parameter ranges. We interpret our results for strong interactions using a fermionization picture and discuss experimental relevance.
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Affiliation(s)
- Zhaoxuan Zhu
- CPHT, CNRS, Ecole Polytechnique, IP Paris, F-91128 Palaiseau, France
| | - Hepeng Yao
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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5
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Zhang R, Yan Y, Zhou Q. Localization on a Synthetic Hall Cylinder. PHYSICAL REVIEW LETTERS 2021; 126:193001. [PMID: 34047582 DOI: 10.1103/physrevlett.126.193001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
By engineering laser-atom interactions, both Hall ribbons and Hall cylinders as fundamental theoretical tools in condensed matter physics have recently been synthesized in laboratories. Here, we show that turning a synthetic Hall ribbon into a synthetic Hall cylinder could naturally lead to localization. Unlike a Hall ribbon, a Hall cylinder hosts an intrinsic lattice, which arises due to the periodic boundary condition in the azimuthal direction, in addition to the external periodic potential imposed by extra lasers. When these two lattices are incommensurate, localization may occur on a synthetic Hall cylinder. Near the localization-delocalization transitions, physical observables strongly depend on the axial magnetic flux, providing us a sensitive means to probe either the transition or the axial flux using one another. In the irrational limit, physical observables are no longer affected by the axial flux, signifying a scheme to suppress decoherence induced by fluctuations of the axial flux.
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Affiliation(s)
- Ren Zhang
- School of Physics, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Yangqian Yan
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Qi Zhou
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
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6
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Gautier R, Yao H, Sanchez-Palencia L. Strongly Interacting Bosons in a Two-Dimensional Quasicrystal Lattice. PHYSICAL REVIEW LETTERS 2021; 126:110401. [PMID: 33798372 DOI: 10.1103/physrevlett.126.110401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
Quasicrystals exhibit exotic properties inherited from the self-similarity of their long-range ordered, yet aperiodic, structure. The recent realization of optical quasicrystal lattices paves the way to the study of correlated Bose fluids in such structures, but the regime of strong interactions remains largely unexplored, both theoretically and experimentally. Here, we determine the quantum phase diagram of two-dimensional correlated bosons in an eightfold quasicrystal potential. Using large-scale quantum Monte Carlo calculations, we demonstrate a superfluid-to-Bose glass transition and determine the critical line. Moreover, we show that strong interactions stabilize Mott insulator phases, some of which have spontaneously broken eightfold symmetry. Our results are directly relevant to current generation experiments and, in particular, drive prospects to the observation of the still elusive Bose glass phase in two dimensions and exotic Mott phases.
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Affiliation(s)
- Ronan Gautier
- CPHT, CNRS, Ecole Polytechnique, IP Paris, F-91128 Palaiseau, France
| | - Hepeng Yao
- CPHT, CNRS, Ecole Polytechnique, IP Paris, F-91128 Palaiseau, France
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7
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Yao H, Giamarchi T, Sanchez-Palencia L. Lieb-Liniger Bosons in a Shallow Quasiperiodic Potential: Bose Glass Phase and Fractal Mott Lobes. PHYSICAL REVIEW LETTERS 2020; 125:060401. [PMID: 32845659 DOI: 10.1103/physrevlett.125.060401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
The emergence of a compressible insulator phase, known as the Bose glass, is characteristic of the interplay of interactions and disorder in correlated Bose fluids. While widely studied in tight-binding models, its observation remains elusive owing to stringent temperature effects. Here we show that this issue may be overcome by using Lieb-Liniger bosons in shallow quasiperiodic potentials. A Bose glass, surrounded by superfluid and Mott phases, is found above a critical potential and for finite interactions. At finite temperature, we show that the melting of the Mott lobes is characteristic of a fractal structure and find that the Bose glass is robust against thermal fluctuations up to temperatures accessible in quantum gases. Our results raise questions about the universality of the Bose glass transition in such shallow quasiperiodic potentials.
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Affiliation(s)
- Hepeng Yao
- CPHT, CNRS, Institut Polytechnique de Paris, Route de Saclay 91128 Palaiseau, France
| | - Thierry Giamarchi
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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8
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Hsueh YW, Hsueh CH, Wu WC. Thermalization in a Quantum Harmonic Oscillator with Random Disorder. ENTROPY 2020; 22:e22080855. [PMID: 33286626 PMCID: PMC7517456 DOI: 10.3390/e22080855] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/14/2020] [Accepted: 07/30/2020] [Indexed: 12/02/2022]
Abstract
We propose a possible scheme to study the thermalization in a quantum harmonic oscillator with random disorder. Our numerical simulation shows that through the effect of random disorder, the system can undergo a transition from an initial nonequilibrium state to a equilibrium state. Unlike the classical damped harmonic oscillator where total energy is dissipated, total energy of the disordered quantum harmonic oscillator is conserved. In particular, at equilibrium the initial mechanical energy is transformed to the thermodynamic energy in which kinetic and potential energies are evenly distributed. Shannon entropy in different bases are shown to yield consistent results during the thermalization.
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Affiliation(s)
- Ya-Wei Hsueh
- Department of Physics, National Central University, Jhong-li 32001, Taiwan;
| | - Che-Hsiu Hsueh
- Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan
- Correspondence: (C.-H.H.); (W.-C.W.)
| | - Wen-Chin Wu
- Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan
- Correspondence: (C.-H.H.); (W.-C.W.)
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9
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Sakhel RR, Sakhel AR. Effect of trapping geometry on the parametric resonances in a disordered Bose-Einstein condensate driven by an oscillating potential. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:315401. [PMID: 32160602 DOI: 10.1088/1361-648x/ab7f06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 03/11/2020] [Indexed: 06/10/2023]
Abstract
We report parametric resonances (PRs) in a numerical investigation of a driven one-dimensional, interacting, and disordered Bose-Einstein condensate (BEC) confined in different traps. The BEC is excited by an oscillating Gaussian obstacle along a broad range of driving frequencies Ω. The PRs are detected via a quantity that is closely related to the time-average of the kinetic energy. The significant result of this work is that the trapping geometry plays a major role in defining the values of Ω at which PRs arise and controls their response to disorder. As such, it reveals the interplay of trapping geometry and disorder in these resonances. The dynamics of the modal coefficientC0(t) as well as that of the phase-mismatchδ(t) between theC0(t) andC1(t) are examined at and away from PR. At PR, |C0(t)| is generally found to be lower in magnitude than away from it, demonstrating that the atoms leave then= 0 ground state towards higher states. In the harmonic oscillator trap, the dynamic pattern ofδ(t) is found to be quite robust against changes in the disorder strength contrary to the box potential. This is because in the box the ratio of the random-potential and kinetic energies is higher than in the harmonic trap signaling that the influence of disorder is weaker in the latter.
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Affiliation(s)
- Roger R Sakhel
- Department of Physics, Faculty of Science, Isra University, Amman 11622, Jordan
| | - Asaad R Sakhel
- Department of Physics, Faculty of Science, Balqa Applied University, Salt 19117, Jordan
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10
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Yao H, Khoudli H, Bresque L, Sanchez-Palencia L. Critical Behavior and Fractality in Shallow One-Dimensional Quasiperiodic Potentials. PHYSICAL REVIEW LETTERS 2019; 123:070405. [PMID: 31491103 DOI: 10.1103/physrevlett.123.070405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Indexed: 06/10/2023]
Abstract
Quasiperiodic systems offer an appealing intermediate between long-range ordered and genuine disordered systems, with unusual critical properties. One-dimensional models that break the so-called self-dual symmetry usually display a mobility edge, similarly as truly disordered systems in a dimension strictly higher than two. Here, we determine the critical localization properties of single particles in shallow, one-dimensional, quasiperiodic models and relate them to the fractal character of the energy spectrum. On the one hand, we determine the mobility edge and show that it separates the localized and extended phases, with no intermediate phase. On the other hand, we determine the critical potential amplitude and find the universal critical exponent ν≃1/3. We also study the spectral Hausdorff dimension and show that it is nonuniversal but always smaller than unity, hence showing that the spectrum is nowhere dense. Finally, applications to ongoing studies of Anderson localization, Bose-glass physics, and many-body localization in ultracold atoms are discussed.
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Affiliation(s)
- Hepeng Yao
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, F-91128 Palaiseau, France
| | - Hakim Khoudli
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, F-91128 Palaiseau, France
| | - Léa Bresque
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, F-91128 Palaiseau, France
| | - Laurent Sanchez-Palencia
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, F-91128 Palaiseau, France
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11
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Abstract
We present a field-theory description of ultracold bosonic atoms in the presence of a disordered external potential. By means of functional integration techniques, we aim to investigate and review the interplay between disordered energy landscapes and fluctuations, both thermal and quantum ones. Within the broken-symmetry phase, up to the Gaussian level of approximation, the disorder contribution crucially modifies both the condensate depletion and the superfluid response. Remarkably, it is found that the ordered (i.e., superfluid) phase can be destroyed also in regimes where the random external potential is suitable for a perturbative analysis. We analyze the simplest case of quenched disorder and then we move to present the implementation of the replica trick for ultracold bosonic systems. In both cases, we discuss strengths and limitations of the reviewed approach, paying specific attention to possible extensions and the most recent experimental outputs.
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12
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Huang C, Shang C, Li J, Dong L, Ye F. Localization and Anderson delocalization of light in fractional dimensions with a quasi-periodic lattice. OPTICS EXPRESS 2019; 27:6259-6267. [PMID: 30876214 DOI: 10.1364/oe.27.006259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 01/26/2019] [Indexed: 06/09/2023]
Abstract
We address the properties of wavepacket localization-delocalization transition (LDT) in fractional dimensions with a quasi-periodic lattice. The LDT point, which is generally determined by the competition between two sub-lattices comprising the quasi-periodic lattice, turns out to be inversely proportional to the Lévy index. Surprisingly, we find that, in the presence of weak structural disorder, anti-Anderson localization occurs, i.e., the introduced disorder results in an increasing of the size of the linear modes. Inclusion of a weak focusing nonlinearity is shown to improve localization. The propagation simulation achieves excellent agreement with the linear and nonlinear eigenmode analysis.
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13
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Makrides C, Li M, Tiesinga E, Kotochigova S. Fractal universality in near-threshold magnetic lanthanide dimers. SCIENCE ADVANCES 2018; 4:eaap8308. [PMID: 29487908 PMCID: PMC5817933 DOI: 10.1126/sciadv.aap8308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/12/2018] [Indexed: 06/08/2023]
Abstract
Ergodic quantum systems are often quite alike, whereas nonergodic, fractal systems are unique and display characteristic properties. We explore one of these fractal systems, weakly bound dysprosium lanthanide molecules, in an external magnetic field. As recently shown, colliding ultracold magnetic dysprosium atoms display a soft chaotic behavior with a small degree of disorder. We broaden this classification by investigating the generalized inverse participation ratio and fractal dimensions for large sets of molecular wave functions. Our exact close-coupling simulations reveal a dynamic phase transition from partially localized states to totally delocalized states and universality in its distribution by increasing the magnetic field strength to only a hundred Gauss (or 10 mT). Finally, we prove the existence of nonergodic delocalized phase in the system and explain the violation of ergodicity by strong coupling between near-threshold molecular states and the nearby continuum.
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Affiliation(s)
- Constantinos Makrides
- Department of Physics, Temple University, Philadelphia, PA 19122–6082, USA
- Joint Quantum Institute and Joint Center for Quantum Information and Computer Science, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD 20899, USA
| | - Ming Li
- Department of Physics, Temple University, Philadelphia, PA 19122–6082, USA
| | - Eite Tiesinga
- Joint Quantum Institute and Joint Center for Quantum Information and Computer Science, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD 20899, USA
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14
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Yan M, Hui HY, Rigol M, Scarola VW. Equilibration Dynamics of Strongly Interacting Bosons in 2D Lattices with Disorder. PHYSICAL REVIEW LETTERS 2017; 119:073002. [PMID: 28949694 DOI: 10.1103/physrevlett.119.073002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Indexed: 06/07/2023]
Abstract
Motivated by recent optical lattice experiments [J.-y. Choi et al., Science 352, 1547 (2016)SCIEAS0036-807510.1126/science.aaf8834], we study the dynamics of strongly interacting bosons in the presence of disorder in two dimensions. We show that Gutzwiller mean-field theory (GMFT) captures the main experimental observations, which are a result of the competition between disorder and interactions. Our findings highlight the difficulty in distinguishing glassy dynamics, which can be captured by GMFT, and many-body localization, which cannot be captured by GMFT, and indicate the need for further experimental studies of this system.
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Affiliation(s)
- Mi Yan
- Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Hoi-Yin Hui
- Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Marcos Rigol
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - V W Scarola
- Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
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15
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Angelone A, Mezzacapo F, Pupillo G. Superglass Phase of Interaction-Blockaded Gases on a Triangular Lattice. PHYSICAL REVIEW LETTERS 2016; 116:135303. [PMID: 27081986 DOI: 10.1103/physrevlett.116.135303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 06/05/2023]
Abstract
We investigate the quantum phases of monodispersed bosonic gases confined to a triangular lattice and interacting via a class of soft-shoulder potentials. The latter correspond to soft-core potentials with an additional hard-core onsite interaction. Using exact quantum Monte Carlo simulations, we show that the low temperature phases for weak and strong interactions following a temperature quench are a homogeneous superfluid and a glass, respectively. The latter is an insulating phase characterized by inhomogeneity in the density distribution and structural disorder. Remarkably, we find that for intermediate interaction strengths a superglass occurs in an extended region of the phase diagram, where glassy behavior coexists with a sizable finite superfluid fraction. This glass phase is obtained in the absence of geometrical frustration or external disorder and is a result of the competition of quantum fluctuations and cluster formation in the corresponding classical ground state. For high enough temperature, the glass and superglass turn into a floating stripe solid and a supersolid, respectively. Given the simplicity and generality of the model, these phases should be directly relevant for state-of-the-art experiments with Rydberg-dressed atoms in optical lattices.
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Affiliation(s)
- Adriano Angelone
- icFRC, IPCMS (UMR 7504) and ISIS (UMR 7006), Université de Strasbourg and CNRS, 67000 Strasbourg, France
| | - Fabio Mezzacapo
- icFRC, IPCMS (UMR 7504) and ISIS (UMR 7006), Université de Strasbourg and CNRS, 67000 Strasbourg, France
| | - Guido Pupillo
- icFRC, IPCMS (UMR 7504) and ISIS (UMR 7006), Université de Strasbourg and CNRS, 67000 Strasbourg, France
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16
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Wang Y, Guo W, Sandvik AW. Anomalous quantum glass of bosons in a random potential in two dimensions. PHYSICAL REVIEW LETTERS 2015; 114:105303. [PMID: 25815942 DOI: 10.1103/physrevlett.114.105303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Indexed: 06/04/2023]
Abstract
We present a quantum Monte Carlo study of the "quantum glass" phase of the two-dimensional Bose-Hubbard model with random potentials at filling ρ=1. In the narrow region between the Mott and superfluid phases, the compressibility has the form κ∼exp(-b/T^{α})+c with α<1 and c vanishing or very small. Thus, at T=0 the system is either incompressible (a Mott glass) or nearly incompressible (a Mott-glass-like anomalous Bose glass). At stronger disorder, where a glass reappears from the superfluid, we find a conventional highly compressible Bose glass. On a path connecting these states, away from the superfluid at larger Hubbard repulsion, a change of the disorder strength by only 10% changes the low-temperature compressibility by more than 4 orders of magnitude, lending support to two types of glass states separated by a phase transition or a sharp crossover.
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Affiliation(s)
- Yancheng Wang
- Department of Physics, Beijing Normal University, Beijing 100875, China
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenan Guo
- Department of Physics, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Anders W Sandvik
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA
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17
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Habibian H, Winter A, Paganelli S, Rieger H, Morigi G. Bose-Glass phases of ultracold atoms due to cavity backaction. PHYSICAL REVIEW LETTERS 2013; 110:075304. [PMID: 25166381 DOI: 10.1103/physrevlett.110.075304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 11/16/2012] [Indexed: 06/03/2023]
Abstract
We determine the quantum ground-state properties of ultracold bosonic atoms interacting with the mode of a high-finesse resonator. The atoms are confined by an external optical lattice, whose period is incommensurate with the cavity mode wavelength, and are driven by a transverse laser, which is resonant with the cavity mode. While for pointlike atoms photon scattering into the cavity is suppressed, for sufficiently strong lasers quantum fluctuations can support the buildup of an intracavity field, which in turn amplifies quantum fluctuations. The dynamics is described by a Bose-Hubbard model where the coefficients due to the cavity field depend on the atomic density at all lattice sites. Quantum Monte Carlo simulations and mean-field calculations show that, for large parameter regions, cavity backaction forces the atoms into clusters with a checkerboard density distribution. Here, the ground state lacks superfluidity and possesses finite compressibility, typical of a Bose glass. This system constitutes a novel setting where quantum fluctuations give rise to effects usually associated with disorder.
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Affiliation(s)
- Hessam Habibian
- Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany and Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - André Winter
- Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany
| | - Simone Paganelli
- Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Heiko Rieger
- Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany
| | - Giovanna Morigi
- Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany
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18
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Hrahsheh F, Vojta T. Disordered bosons in one dimension: from weak- to strong-randomness criticality. PHYSICAL REVIEW LETTERS 2012; 109:265303. [PMID: 23368577 DOI: 10.1103/physrevlett.109.265303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Indexed: 06/01/2023]
Abstract
We investigate the superfluid-insulator quantum phase transition of one-dimensional bosons with off-diagonal disorder by means of large-scale Monte Carlo simulations. For weak disorder, we find the transition to be in the same universality class as the superfluid-Mott insulator transition of the clean system. The nature of the transition changes for stronger disorder. Beyond a critical disorder strength, we find nonuniversal, disorder-dependent critical behavior. We compare our results to recent perturbative and strong-disorder renormalization group predictions. We also discuss experimental implications as well as extensions of our results to other systems.
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Affiliation(s)
- Fawaz Hrahsheh
- Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
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19
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Söyler SG, Kiselev M, Prokof'ev NV, Svistunov BV. Phase diagram of the commensurate two-dimensional disordered Bose-Hubbard model. PHYSICAL REVIEW LETTERS 2011; 107:185301. [PMID: 22107640 DOI: 10.1103/physrevlett.107.185301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Indexed: 05/31/2023]
Abstract
We establish the full ground state phase diagram of the disordered Bose-Hubbard model in two dimensions at a unity filling factor via quantum Monte Carlo simulations. Similarly to the three-dimensional case we observe extended superfluid regions persisting up to extremely large values of disorder and interaction strength which, however, have small superfluid fractions and thus low transition temperatures. In the vicinity of the superfluid-insulator transition of the pure system, we observe an unexpectedly weak--almost not resolvable--sensitivity of the critical interaction to the strength of (weak) disorder.
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Affiliation(s)
- S G Söyler
- The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34151 Trieste, Italy
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20
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Pezzé L, Sanchez-Palencia L. Localized and extended states in a disordered trap. PHYSICAL REVIEW LETTERS 2011; 106:040601. [PMID: 21405316 DOI: 10.1103/physrevlett.106.040601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Revised: 12/08/2010] [Indexed: 05/30/2023]
Abstract
We study Anderson localization in a disordered potential combined with an inhomogeneous trap. We show that the spectrum displays both localized and extended states, which coexist at intermediate energies. In the region of coexistence, we find that the extended states result from confinement by the trap and are weakly affected by the disorder. Conversely, the localized states correspond to eigenstates of the disordered potential, which are only affected by the trap via an inhomogeneous energy shift. These results are relevant to disordered quantum gases and we propose a realistic scheme to observe the coexistence of localized and extended states in these systems.
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Affiliation(s)
- Luca Pezzé
- Laboratoire Charles Fabry de l'Institut d'Optique, CNRS and Université Paris-Sud, Palaiseau, France
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21
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Fontanesi L, Wouters M, Savona V. Superfluid to Bose-Glass transition in a 1D weakly interacting Bose gas. PHYSICAL REVIEW LETTERS 2009; 103:030403. [PMID: 19659256 DOI: 10.1103/physrevlett.103.030403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/18/2009] [Indexed: 05/28/2023]
Abstract
We study the one-dimensional Bose gas in spatially correlated disorder at zero temperature, using an extended density-phase Bogoliubov method. We analyze, in particular, the decay of the one-body density matrix and the behavior of the Bogoliubov excitations across the phase boundary. We observe that the transition to the Bose-glass phase is marked by a power-law divergence of the density of states at low energy. A measure of the localization length displays a power-law energy dependence in both regions, with the exponent equal to -1 at the boundary. We draw the phase diagram of the superfluid-insulator transition in the limit of small interaction strength.
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Affiliation(s)
- Luca Fontanesi
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne EPFL, CH-1015 Lausanne, Switzerland.
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22
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Delande D, Zakrzewski J. Compression as a tool to detect bose glass in a cold atomic gas. PHYSICAL REVIEW LETTERS 2009; 102:085301. [PMID: 19257748 DOI: 10.1103/physrevlett.102.085301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Indexed: 05/27/2023]
Abstract
We suggest that measuring the variation of the radius of an atomic cloud when the harmonic trap confinement is varied makes it possible to monitor the disappearance of the insulating Mott phase of an ultracold atomic gas trapped in a disordered optical lattice. This paves the way for an unambiguous identification of a Bose glass phase in the system.
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Affiliation(s)
- Dominique Delande
- Laboratoire Kastler-Brossel, Université Pierre et Marie Curie-Paris 6, ENS, CNRS; 4 Place Jussieu, F-75005 Paris, France
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23
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White M, Pasienski M, McKay D, Zhou SQ, Ceperley D, Demarco B. Strongly interacting bosons in a disordered optical lattice. PHYSICAL REVIEW LETTERS 2009; 102:055301. [PMID: 19257516 DOI: 10.1103/physrevlett.102.055301] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Indexed: 05/27/2023]
Abstract
We experimentally probe the properties of the disordered Bose-Hubbard model using an atomic Bose-Einstein condensate trapped in a 3D disordered optical lattice. Controllable disorder is introduced using a fine-grained optical speckle field with features comparable in size to the lattice spacing along every lattice direction. A precision measurement of the disordering potential is used to compute the single-particle parameters of the system. To constrain theories of the disordered Bose Hubbard model, we have measured the change in condensate fraction as a function of disorder strength for several different ratios of tunneling to interaction energy. We observe disorder-induced, reversible suppression of condensate fraction for superfluid and coexisting superfluid-Mott-insulator phases.
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Affiliation(s)
- M White
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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24
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Vicencio RA, Flach S. Control of wave packet spreading in nonlinear finite disordered lattices. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:016217. [PMID: 19257132 DOI: 10.1103/physreve.79.016217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Indexed: 05/27/2023]
Abstract
In the absence of nonlinearity all normal modes (NMs) of a chain with disorder are spatially localized (Anderson localization). We study the action of nonlinearity, whose strength is ramped linearly in time. It leads to a spreading of a wave packet due to interaction with and population of distant NMs. Eventually nonlinearity-induced frequency shifts take over and the wave packet becomes self-trapped. On finite chains a critical ramping speed is obtained, which separates delocalized final states from localized ones. The critical value depends on the strength of disorder and is largest when the localization length matches the system size.
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Affiliation(s)
- Rodrigo A Vicencio
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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25
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Edwards EE, Beeler M, Hong T, Rolston SL. Adiabaticity and localization in one-dimensional incommensurate lattices. PHYSICAL REVIEW LETTERS 2008; 101:260402. [PMID: 19437625 DOI: 10.1103/physrevlett.101.260402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We experimentally investigate the role of localization on the adiabaticity of loading a Bose-Einstein condensate into a one-dimensional optical potential comprised of a shallow primary lattice plus one or two perturbing lattice(s) of incommensurate period. We find that even a very weak perturbation causes dramatic changes in the momentum distribution and makes adiabatic loading of the combined lattice much more difficult than for a single period lattice. We interpret our results using a band-structure model and the one-dimensional Gross-Pitaevskii equation.
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Affiliation(s)
- E E Edwards
- Joint Quantum Institute and Department of Physics, University of Maryland, National Institute of Standards and Technology, College Park, Maryland 20742, USA
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26
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Hartung M, Wellens T, Müller CA, Richter K, Schlagheck P. Coherent backscattering of Bose-Einstein condensates in two-dimensional disorder potentials. PHYSICAL REVIEW LETTERS 2008; 101:020603. [PMID: 18764169 DOI: 10.1103/physrevlett.101.020603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 06/14/2008] [Indexed: 05/26/2023]
Abstract
We study quantum transport of an interacting Bose-Einstein condensate in a two-dimensional disorder potential. In the limit of a vanishing atom-atom interaction, a sharp cone in the angle-resolved density of the scattered matter wave is observed, arising from constructive interference between amplitudes propagating along reversed scattering paths. Weak interaction transforms this coherent backscattering peak into a pronounced dip, indicating destructive instead of constructive interference. We reproduce this result, obtained from the numerical integration of the Gross-Pitaevskii equation, by a diagrammatic theory of weak localization in the presence of nonlinearity.
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Affiliation(s)
- Michael Hartung
- Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany
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27
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Roati G, D’Errico C, Fallani L, Fattori M, Fort C, Zaccanti M, Modugno G, Modugno M, Inguscio M. Anderson localization of a non-interacting Bose–Einstein condensate. Nature 2008; 453:895-8. [DOI: 10.1038/nature07071] [Citation(s) in RCA: 1256] [Impact Index Per Article: 78.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 05/06/2008] [Indexed: 11/09/2022]
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28
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Direct observation of Anderson localization of matter waves in a controlled disorder. Nature 2008; 453:891-4. [DOI: 10.1038/nature07000] [Citation(s) in RCA: 1191] [Impact Index Per Article: 74.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 04/09/2008] [Indexed: 11/08/2022]
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29
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Sengupta P, Haas S. Quantum glass phases in the disordered Bose-Hubbard model. PHYSICAL REVIEW LETTERS 2007; 99:050403. [PMID: 17930735 DOI: 10.1103/physrevlett.99.050403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2006] [Indexed: 05/25/2023]
Abstract
The phase diagram of the Bose-Hubbard model in the presence of off-diagonal disorder is determined using quantum Monte Carlo simulations. A sequence of quantum glass phases intervene at the interface between the Mott insulating and the superfluid phases of the clean system. In addition to the standard Bose glass phase, the coexistence of gapless and gapped regions close to the Mott insulating phase leads to a novel Mott glass regime which is incompressible yet gapless. Numerical evidence for the properties of these phases is given in terms of global (compressibility, superfluid stiffness) and local (compressibility, momentum distribution) observables.
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Affiliation(s)
- Pinaki Sengupta
- T-CNLS and NHMFL, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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30
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Sanchez-Palencia L, Clément D, Lugan P, Bouyer P, Shlyapnikov GV, Aspect A. Anderson localization of expanding Bose-Einstein condensates in random potentials. PHYSICAL REVIEW LETTERS 2007; 98:210401. [PMID: 17677751 DOI: 10.1103/physrevlett.98.210401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Indexed: 05/16/2023]
Abstract
We show that the expansion of an initially confined interacting 1D Bose-Einstein condensate can exhibit Anderson localization in a weak random potential with correlation length sigma(R). For speckle potentials the Fourier transform of the correlation function vanishes for momenta k>2/sigma(R) so that the Lyapunov exponent vanishes in the Born approximation for k>1/sigma(R). Then, for the initial healing length of the condensate xi(in)>sigma(R) the localization is exponential, and for xi(in)<sigma(R) it changes to algebraic.
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Affiliation(s)
- L Sanchez-Palencia
- Laboratoire Charles Fabry de l'Institut d'Optique, CNRS and Univ. Paris-Sud, Campus Polytechnique, RD 128, F-91127 Palaiseau cedex, France
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31
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Fallani L, Lye JE, Guarrera V, Fort C, Inguscio M. Ultracold atoms in a disordered crystal of light: towards a bose glass. PHYSICAL REVIEW LETTERS 2007; 98:130404. [PMID: 17501171 DOI: 10.1103/physrevlett.98.130404] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Indexed: 05/15/2023]
Abstract
We use a bichromatic optical lattice to experimentally realize a disordered system of ultracold strongly interacting 87Rb bosons. In the absence of disorder, the atoms are pinned by repulsive interactions in the sites of an ideal optical crystal, forming one-dimensional Mott-insulator states. We measure the excitation spectrum of the system as a function of disorder strength and characterize its phase-coherence properties with a time-of-flight technique. Increasing disorder, we observe a broadening of the Mott-insulator resonances and the transition to a state with vanishing long-range phase coherence and a flat density of excitations, which suggest the formation of a Bose-glass phase.
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Affiliation(s)
- L Fallani
- LENS European Laboratory for Nonlinear Spectroscopy and Dipartimento di Fisica, Università di Firenze, via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy.
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32
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Palmer RN, Jaksch D. High-field fractional quantum Hall effect in optical lattices. PHYSICAL REVIEW LETTERS 2006; 96:180407. [PMID: 16712350 DOI: 10.1103/physrevlett.96.180407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2005] [Indexed: 05/09/2023]
Abstract
We consider interacting bosonic atoms in an optical lattice subject to a large simulated magnetic field. We develop a model similar to a bilayer fractional quantum Hall system valid near simple rational numbers of magnetic flux quanta per lattice cell. Then we calculate its ground state, magnetic lengths, fractional fillings, and find unexpected sign changes in the Hall current. Finally we study methods for detecting these novel features via shot noise and Hall current measurements.
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Affiliation(s)
- R N Palmer
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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33
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Kuhn RC, Miniatura C, Delande D, Sigwarth O, Müller CA. Localization of matter waves in two-dimensional disordered optical potentials. PHYSICAL REVIEW LETTERS 2005; 95:250403. [PMID: 16384437 DOI: 10.1103/physrevlett.95.250403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Indexed: 05/05/2023]
Abstract
We consider ultracold atoms in 2D disordered optical potentials and calculate microscopic quantities characterizing matter wave quantum transport in the noninteracting regime. We derive the diffusion constant as a function of all relevant microscopic parameters and show that coherent multiple scattering induces significant weak localization effects. In particular, we find that even the strong localization regime is accessible with current experimental techniques and calculate the corresponding localization length.
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Affiliation(s)
- R C Kuhn
- Physikalisches Institut, Universität Bayreuth, D-95440 Bayreuth, Germany
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34
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Calsamiglia J, Hartmann L, Dür W, Briegel HJ. Spin gases: quantum entanglement driven by classical kinematics. PHYSICAL REVIEW LETTERS 2005; 95:180502. [PMID: 16383883 DOI: 10.1103/physrevlett.95.180502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Indexed: 05/05/2023]
Abstract
A spin gas is a natural extension of a classical gas. It consists of a large number of particles whose (random) motion is described classically, but, in addition, have internal (quantum mechanical) degrees of freedom that interact during collisions. For specific types of quantum interactions we determine the entanglement that occurs naturally in such systems. We analyze how the evolution of the quantum state is determined by the underlying classical kinematics of the gas. For the Boltzmann gas, we calculate the rate at which entanglement is produced and characterize the entanglement properties of the equilibrium state.
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Affiliation(s)
- J Calsamiglia
- Institut für Theoretische Physik, Universität Innsbruck, Innsbruck, Austria
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35
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Fort C, Fallani L, Guarrera V, Lye JE, Modugno M, Wiersma DS, Inguscio M. Effect of optical disorder and single defects on the expansion of a Bose-Einstein condensate in a one-dimensional waveguide. PHYSICAL REVIEW LETTERS 2005; 95:170410. [PMID: 16383807 DOI: 10.1103/physrevlett.95.170410] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Indexed: 05/05/2023]
Abstract
We investigate the one-dimensional expansion of a Bose-Einstein condensate in an optical guide in the presence of a random potential created with optical speckles. With the speckle the expansion of the condensate is strongly inhibited. A detailed investigation has been carried out varying the experimental conditions and checking the expansion when a single optical defect is present. The experimental results are in good agreement with numerical calculations based on the Gross-Pitaevskii equation.
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Affiliation(s)
- C Fort
- LENS, Dipartimento di Fisica and INFM, Università di Firenze, via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy
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36
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Schulte T, Drenkelforth S, Kruse J, Ertmer W, Arlt J, Sacha K, Zakrzewski J, Lewenstein M. Routes towards Anderson-like localization of Bose-Einstein condensates in disordered optical lattices. PHYSICAL REVIEW LETTERS 2005; 95:170411. [PMID: 16383808 DOI: 10.1103/physrevlett.95.170411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Indexed: 05/05/2023]
Abstract
We investigate, both experimentally and theoretically, possible routes towards Anderson-like localization of Bose-Einstein condensates in disordered potentials. The dependence of this quantum interference effect on the nonlinear interactions and the shape of the disorder potential is investigated. Experiments with an optical lattice and a superimposed disordered potential reveal the lack of Anderson localization. A theoretical analysis shows that this absence is due to the large length scale of the disorder potential as well as its screening by the nonlinear interactions. Further analysis shows that incommensurable superlattices should allow for the observation of the crossover from the nonlinear screening regime to the Anderson localized case within realistic experimental parameters.
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Affiliation(s)
- T Schulte
- Institut für Quantenoptik, Universität Hannover, Welfengarten 1, D-30167 Hannover, Germany
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37
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Gimperlein H, Wessel S, Schmiedmayer J, Santos L. Ultracold atoms in optical lattices with random on-site interactions. PHYSICAL REVIEW LETTERS 2005; 95:170401. [PMID: 16383798 DOI: 10.1103/physrevlett.95.170401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Indexed: 05/05/2023]
Abstract
We consider the physics of lattice bosons affected by disordered on-site interparticle interactions. Characteristic qualitative changes in the zero-temperature phase diagram are observed when compared to the case of randomness in the chemical potential. The Mott-insulating regions shrink and eventually vanish for any finite disorder strength beyond a sufficiently large filling factor. Furthermore, at low values of the chemical potential both the superfluid and Mott insulator are stable towards formation of a Bose glass leading to a possibly nontrivial tricritical point. We discuss feasible experimental realizations of our scenario in the context of ultracold atoms on optical lattices.
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Affiliation(s)
- H Gimperlein
- Institut für Theoretische Physik III, Universität Stuttgart, Pfaffenwaldring 57 V, D-70550 Stuttgart, Germany
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38
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Clément D, Varón AF, Hugbart M, Retter JA, Bouyer P, Sanchez-Palencia L, Gangardt DM, Shlyapnikov GV, Aspect A. Suppression of transport of an interacting elongated Bose-Einstein condensate in a random potential. PHYSICAL REVIEW LETTERS 2005; 95:170409. [PMID: 16383806 DOI: 10.1103/physrevlett.95.170409] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Indexed: 05/05/2023]
Abstract
We observe the suppression of the 1D transport of an interacting elongated Bose-Einstein condensate in a random potential with an amplitude that is small compared to the typical energy per atom, dominated by the interaction energy. Numerical calculations reproduce our observations well. We propose a scenario for disorder-induced trapping of the condensate in agreement with our findings.
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Affiliation(s)
- D Clément
- Laboratoire Charles Fabry, Institut d'Optique, Université Paris-Sud XI, 91403 Orsay Cedex, France
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39
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Lye JE, Fallani L, Modugno M, Wiersma DS, Fort C, Inguscio M. Bose-Einstein condensate in a random potential. PHYSICAL REVIEW LETTERS 2005; 95:070401. [PMID: 16196765 DOI: 10.1103/physrevlett.95.070401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Indexed: 05/04/2023]
Abstract
An optical speckle potential is used to investigate the static and dynamic properties of a Bose-Einstein condensate in the presence of disorder. With small levels of disorder, stripes are observed in the expanded density profile and strong damping of dipole and quadrupole oscillations is seen. Uncorrelated frequency shifts of the two modes are measured and are explained using a sum-rules approach and by the numerical solution of the Gross-Pitaevskii equation.
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Affiliation(s)
- J E Lye
- LENS, Dipartimento di Fisica, and INFM Università di Firenze, Sesto Fiorentino (FI), Italy.
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40
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Balabanyan KG, Prokof'ev N, Svistunov B. Superfluid-insulator transition in a commensurate one-dimensional bosonic system with off-diagonal disorder. PHYSICAL REVIEW LETTERS 2005; 95:055701. [PMID: 16090888 DOI: 10.1103/physrevlett.95.055701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Revised: 05/03/2005] [Indexed: 05/03/2023]
Abstract
We study the nature of the superfluid-insulator quantum phase transition in a one-dimensional system of lattice bosons with off-diagonal disorder in the limit of a large integer filling factor. Monte Carlo simulations of two strongly disordered models show that the universality class of the transition in question is the same as that of the superfluid-Mott-insulator transition in a pure system. This result can be explained by disorder self-averaging in the superfluid phase and the applicability of the standard quantum hydrodynamic action. We also formulate the necessary conditions which should be satisfied by the stong-randomness universality class, if one exists.
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Affiliation(s)
- Karén G Balabanyan
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA
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41
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De Martino A, Thorwart M, Egger R, Graham R. Exact results for one-dimensional disordered bosons with strong repulsion. PHYSICAL REVIEW LETTERS 2005; 94:060402. [PMID: 15783709 DOI: 10.1103/physrevlett.94.060402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Indexed: 05/24/2023]
Abstract
We study one-dimensional disordered bosons with strong repulsive interactions. A Bose-Fermi mapping expresses this problem in terms of noninteracting Anderson-localized fermions, whereby known results for the distribution function of the local density of states, the spectral statistics, and density-density correlations can be transferred to this new domain of applicability. We show that disorder destroys bosonic quasi-long-range order by calculating the momentum distribution, and comment on the experimental observability of these predictions in ultracold atomic gases.
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Affiliation(s)
- A De Martino
- Institut für Theoretische Physik, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany
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42
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Altman E, Kafri Y, Polkovnikov A, Refael G. Phase transition in a system of one-dimensional bosons with strong disorder. PHYSICAL REVIEW LETTERS 2004; 93:150402. [PMID: 15524855 DOI: 10.1103/physrevlett.93.150402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Indexed: 05/24/2023]
Abstract
We study one-dimensional disordered bosons at large commensurate filling. Using a real space renormalization group approach, we find a new random fixed point which controls a phase transition from a superfluid to an incompressible Mott glass. The transition can be tuned by changing the disorder distribution even with vanishing interactions. We derive the properties of the transition, which suggest that it is in the Kosterlitz-Thouless universality class.
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Affiliation(s)
- Ehud Altman
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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43
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Lee C. Bose-Einstein condensation of particle-hole pairs in ultracold fermionic atoms trapped within optical lattices. PHYSICAL REVIEW LETTERS 2004; 93:120406. [PMID: 15447239 DOI: 10.1103/physrevlett.93.120406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Indexed: 05/24/2023]
Abstract
We investigate the Bose-Einstein condensation (BEC, superfluidity) of particle-hole pairs in ultracold fermionic atoms with repulsive interactions and arbitrary polarization, which are trapped within optical lattices. In the strongly repulsive limit, the dynamics of particle-hole pairs can be described by a hard-core Bose-Hubbard model. The insulator-superfluid and charge-density-wave- (CDW) superfluid phase transitions can be induced by decreasing and increasing the potential depths with controlling the trapping laser intensity, respectively. The parameter and polarization dependence of the critical temperatures for the ordered states (BEC and/or CDW) are discussed simultaneously.
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Affiliation(s)
- Chaohong Lee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, D-01187 Dresden, Germany.
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Polkovnikov A, Wang DW. Effect of quantum fluctuations on the dipolar motion of bose-einstein condensates in optical lattices. PHYSICAL REVIEW LETTERS 2004; 93:070401. [PMID: 15324216 DOI: 10.1103/physrevlett.93.070401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2003] [Indexed: 05/24/2023]
Abstract
We reexamine dipolar motion of condensate atoms in one-dimensional optical lattices and harmonic magnetic traps including quantum fluctuations within the truncated Wigner approximation. In the strong tunneling limit we reproduce the mean field results with a sharp dynamical transition at the critical displacement. When the tunneling is reduced, on the contrary, strong quantum fluctuations lead to finite damping of condensate oscillations even at infinitesimal displacement. We argue that there is a smooth crossover between the chaotic classical transition at finite displacement and the superfluid-to-insulator phase transition at zero displacement. We further analyze the time dependence of the density fluctuations and of the coherence of the condensate and find several nontrivial dynamical effects, which can be observed in the present experimental conditions.
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Sanpera A, Kantian A, Sanchez-Palencia L, Zakrzewski J, Lewenstein M. Atomic fermi-bose mixtures in inhomogeneous and random lattices: from fermi glass to quantum spin glass and quantum percolation. PHYSICAL REVIEW LETTERS 2004; 93:040401. [PMID: 15323736 DOI: 10.1103/physrevlett.93.040401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Indexed: 05/24/2023]
Abstract
We investigate strongly interacting atomic Fermi-Bose mixtures in inhomogeneous and random optical lattices. We derive an effective Hamiltonian for the system and discuss its low temperature physics. We demonstrate the possibility of controlling the interactions at local level in inhomogeneous but regular lattices. Such a control leads to the achievement of Fermi glass, quantum Fermi spin-glass, and quantum percolation regimes involving bare and/or composite fermions in random lattices.
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Affiliation(s)
- A Sanpera
- Institut de Ciències Fotòniques, 08034 Barcelona, Spain
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