1
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Huai X, Acheampong E, Delles E, Winiarski MJ, Sorolla M, Nassar L, Liang M, Ramette C, Ji H, Scheie A, Calder S, Mourigal M, Tran TT. Noncentrosymmetric Triangular Magnet CaMnTeO 6: Strong Quantum Fluctuations and Role of s 0 versus s 2 Electronic States in Competing Exchange Interactions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2313763. [PMID: 38506567 DOI: 10.1002/adma.202313763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 03/12/2024] [Indexed: 03/21/2024]
Abstract
Noncentrosymmetric triangular magnets offer a unique platform for realizing strong quantum fluctuations. However, designing these quantum materials remains an open challenge attributable to a knowledge gap in the tunability of competing exchange interactions at the atomic level. Here, a new noncentrosymmetric triangular S = 3/2 magnet CaMnTeO6 is created based on careful chemical and physical considerations. The model material displays competing magnetic interactions and features nonlinear optical responses with the capability of generating coherent photons. The incommensurate magnetic ground state of CaMnTeO6 with an unusually large spin rotation angle of 127°(1) indicates that the anisotropic interlayer exchange is strong and competing with the isotropic interlayer Heisenberg interaction. The moment of 1.39(1) µB, extracted from low-temperature heat capacity and neutron diffraction measurements, is only 46% of the expected value of the static moment 3 µB. This reduction indicates the presence of strong quantum fluctuations in the half-integer spin S = 3/2 CaMnTeO6 magnet, which is rare. By comparing the spin-polarized band structure, chemical bonding, and physical properties of AMnTeO6 (A = Ca, Sr, Pb), how quantum-chemical interpretation can illuminate insights into the fundamentals of magnetic exchange interactions, providing a powerful tool for modulating spin dynamics with atomically precise control is demonstrated.
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Affiliation(s)
- Xudong Huai
- Department of Chemistry, Clemson University, Clemson, SC, 29634, USA
| | | | - Erich Delles
- Department of Chemistry, Clemson University, Clemson, SC, 29634, USA
| | - Michał J Winiarski
- Applied Physics and Mathematics and Advanced Materials Center, Gdansk University of Technology, Gdansk, 80-233, Poland
| | - Maurice Sorolla
- Institute of Chemistry, University of the Philippines Diliman, Quezon City, 1101, Philippines
| | - Lila Nassar
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Mingli Liang
- Department of Chemistry, University of Houston, Houston, TX, 77204, USA
| | - Caleb Ramette
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Huiwen Ji
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Allen Scheie
- MPA-Q, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Stuart Calder
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Martin Mourigal
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Thao T Tran
- Department of Chemistry, Clemson University, Clemson, SC, 29634, USA
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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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Shen R, Chen T, Aliyu MM, Qin F, Zhong Y, Loh H, Lee CH. Proposal for Observing Yang-Lee Criticality in Rydberg Atomic Arrays. PHYSICAL REVIEW LETTERS 2023; 131:080403. [PMID: 37683169 DOI: 10.1103/physrevlett.131.080403] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/27/2023] [Accepted: 07/25/2023] [Indexed: 09/10/2023]
Abstract
Yang-Lee edge singularities (YLES) are the edges of the partition function zeros of an interacting spin model in the space of complex control parameters. They play an important role in understanding non-Hermitian phase transitions in many-body physics, as well as characterizing the corresponding nonunitary criticality. Even though such partition function zeroes have been measured in dynamical experiments where time acts as the imaginary control field, experimentally demonstrating such YLES criticality with a physical imaginary field has remained elusive due to the difficulty of physically realizing non-Hermitian many-body models. We provide a protocol for observing the YLES by detecting kinked dynamical magnetization responses due to broken PT symmetry, thus enabling the physical probing of nonunitary phase transitions in nonequilibrium settings. In particular, scaling analyses based on our nonunitary time evolution circuit with matrix product states accurately recover the exponents uniquely associated with the corresponding nonunitary CFT. We provide an explicit proposal for observing YLES criticality in Floquet quenched Rydberg atomic arrays with laser-induced loss, which paves the way towards a universal platform for simulating non-Hermitian many-body dynamical phenomena.
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Affiliation(s)
- Ruizhe Shen
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| | - Tianqi Chen
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798, Singapore
| | - Mohammad Mujahid Aliyu
- Centre for Quantum Technologies, National University of Singapore, 117543 Singapore, Singapore
| | - Fang Qin
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| | - Yin Zhong
- School of Physical Science and Technology and Key Laboratory for Magnetism and Magnetic Materials of the MoE, Lanzhou University, Lanzhou 730000, China
- Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou 730000, China
| | - Huanqian Loh
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
- Centre for Quantum Technologies, National University of Singapore, 117543 Singapore, Singapore
| | - Ching Hua Lee
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
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4
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Hales J, Bajpai U, Liu T, Baykusheva DR, Li M, Mitrano M, Wang Y. Witnessing light-driven entanglement using time-resolved resonant inelastic X-ray scattering. Nat Commun 2023; 14:3512. [PMID: 37316515 DOI: 10.1038/s41467-023-38540-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 05/03/2023] [Indexed: 06/16/2023] Open
Abstract
Characterizing and controlling entanglement in quantum materials is crucial for the development of next-generation quantum technologies. However, defining a quantifiable figure of merit for entanglement in macroscopic solids is theoretically and experimentally challenging. At equilibrium the presence of entanglement can be diagnosed by extracting entanglement witnesses from spectroscopic observables and a nonequilibrium extension of this method could lead to the discovery of novel dynamical phenomena. Here, we propose a systematic approach to quantify the time-dependent quantum Fisher information and entanglement depth of transient states of quantum materials with time-resolved resonant inelastic x-ray scattering. Using a quarter-filled extended Hubbard model as an example, we benchmark the efficiency of this approach and predict a light-enhanced many-body entanglement due to the proximity to a phase boundary. Our work sets the stage for experimentally witnessing and controlling entanglement in light-driven quantum materials via ultrafast spectroscopic measurements.
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Affiliation(s)
- Jordyn Hales
- Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634, USA
| | - Utkarsh Bajpai
- Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634, USA
| | - Tongtong Liu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | | | - Mingda Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Matteo Mitrano
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA.
| | - Yao Wang
- Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634, USA.
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5
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Abstract
We address spin transport in the easy-axis Heisenberg spin chain subject to different integrability-breaking perturbations. We find subdiffusive spin transport characterized by dynamical exponent z = 4 up to a timescale parametrically long in the anisotropy. In the limit of infinite anisotropy, transport is subdiffusive at all times; for finite anisotropy, one eventually recovers diffusion at late times but with a diffusion constant independent of the strength of the perturbation and solely fixed by the value of the anisotropy. We provide numerical evidence for these findings, and we show how they can be understood in terms of the dynamical screening of the relevant quasiparticle excitations and effective dynamical constraints. Our results show that the diffusion constant of near-integrable diffusive spin chains is generically not perturbative in the integrability-breaking strength.
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6
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Senaratne R, Cavazos-Cavazos D, Wang S, He F, Chang YT, Kafle A, Pu H, Guan XW, Hulet RG. Spin-charge separation in a one-dimensional Fermi gas with tunable interactions. Science 2022; 376:1305-1308. [PMID: 35709259 DOI: 10.1126/science.abn1719] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Ultracold atoms confined to periodic potentials have proven to be a powerful tool for quantum simulation of complex many-body systems. We confine fermions to one dimension to realize the Tomonaga-Luttinger liquid model, which describes the highly collective nature of their low-energy excitations. We use Bragg spectroscopy to directly excite either the spin or charge waves for various strengths of repulsive interaction. We observe that the velocity of the spin and charge excitations shift in opposite directions with increasing interaction, a hallmark of spin-charge separation. The excitation spectra are in quantitative agreement with the exact solution of the Yang-Gaudin model and the Tomonaga-Luttinger liquid theory. Furthermore, we identify effects of nonlinear corrections to this theory that arise from band curvature and back-scattering.
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Affiliation(s)
- Ruwan Senaratne
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | | | - Sheng Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feng He
- University of Chinese Academy of Sciences, Beijing 100049, China.,International School for Advanced Studies (SISSA) and National Institute of Nuclear Physics (INFN), Sezione di Trieste, 34136 Trieste, Italy
| | - Ya-Ting Chang
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - Aashish Kafle
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - Han Pu
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - Xi-Wen Guan
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Department of Theoretical Physics, RSPE, Australian National University, Canberra, ACT 0200, Australia
| | - Randall G Hulet
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
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7
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Lozano-Méndez K, Cásares AH, Caballero-Benítez SF. Spin Entanglement and Magnetic Competition via Long-Range Interactions in Spinor Quantum Optical Lattices. PHYSICAL REVIEW LETTERS 2022; 128:080601. [PMID: 35275654 DOI: 10.1103/physrevlett.128.080601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/20/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Quantum matter at ultralow temperatures offers a test bed for analyzing and controlling desired properties in strongly correlated systems. Under typical conditions the nature of the atoms fixes the magnetic character of the system. Beyond classical light potentials leading to optical lattices and short-range interactions, high-Q cavities introduce novel dynamics into the system via the quantumness of light. Here we propose a theoretical model and we analyze it using exact diagonalization and density matrix renormalization group simulations. We explore the effects of cavity mediated long-range magnetic interactions and optical lattices in ultracold matter. We find that global interactions modify the underlying magnetic character of the system while introducing competition scenarios. Antiferromagnetic correlated bosonic matter emerges in conditions beyond what nature typically provides. These allow new alternatives toward the design of robust mechanisms for quantum information purposes, exploiting the properties of magnetic phases of strongly correlated quantum matter.
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Affiliation(s)
- Karen Lozano-Méndez
- Instituto de Física, LSCSC-LANMAC, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Alejandro H Cásares
- Instituto de Física, LSCSC-LANMAC, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
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8
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Bhattacharya U, Grass T, Bachtold A, Lewenstein M, Pistolesi F. Phonon-Induced Pairing in Quantum Dot Quantum Simulator. NANO LETTERS 2021; 21:9661-9667. [PMID: 34757742 PMCID: PMC8631338 DOI: 10.1021/acs.nanolett.1c03457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Quantum simulations can provide new insights into the physics of strongly correlated electronic systems. A well-studied system, but still open in many regards, is the Hubbard-Holstein Hamiltonian, where electronic repulsion is in competition with attraction generated by the electron-phonon coupling. In this context, we study the behavior of four quantum dots in a suspended carbon nanotube and coupled to its flexural degrees of freedom. The system is described by a Hamiltonian of the Hubbard-Holstein class, where electrons on different sites interact with the same phonon. We find that the system presents a transition from the Mott insulating state to a polaronic state, with the appearance of pairing correlations and the breaking of the translational symmetry. These findings will motivate further theoretical and experimental efforts to employ nanoelectromechanical systems to simulate strongly correlated systems with electron-phonon interactions.
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Affiliation(s)
- Utso Bhattacharya
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, Castelldefels, Barcelona 08860, Spain
- Max-Planck-Institut
für Quantenoptik, D-85748 Garching, Germany
| | - Tobias Grass
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Adrian Bachtold
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Maciej Lewenstein
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, Castelldefels, Barcelona 08860, Spain
- ICREA, Pg. Lluis Companys
23, 08010 Barcelona, Spain
| | - Fabio Pistolesi
- Univ.
Bordeaux, CNRS, LOMA, UMR 5798, F-33400 Talence, France
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9
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Koepsell J, Bourgund D, Sompet P, Hirthe S, Bohrdt A, Wang Y, Grusdt F, Demler E, Salomon G, Gross C, Bloch I. Microscopic evolution of doped Mott insulators from polaronic metal to Fermi liquid. Science 2021; 374:82-86. [PMID: 34591626 DOI: 10.1126/science.abe7165] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Joannis Koepsell
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - Dominik Bourgund
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - Pimonpan Sompet
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - Sarah Hirthe
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - Annabelle Bohrdt
- Munich Center for Quantum Science and Technology, 80799 München, Germany.,Department of Physics and Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany
| | - Yao Wang
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.,Department of Physics and Astronomy, Clemson University, Clemson, SC 29631, USA
| | - Fabian Grusdt
- Munich Center for Quantum Science and Technology, 80799 München, Germany.,Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 München, Germany
| | - Eugene Demler
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Guillaume Salomon
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany.,Institut für Laserphysik, Universität Hamburg, 22761 Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761 Hamburg, Germany
| | - Christian Gross
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany.,Physikalisches Institut, Eberhard Karls Universität Tübingen, 72076 Tübingen, Germany
| | - Immanuel Bloch
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.,Munich Center for Quantum Science and Technology, 80799 München, Germany.,Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 München, Germany
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10
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Masi L, Petrucciani T, Ferioli G, Semeghini G, Modugno G, Inguscio M, Fattori M. Spatial Bloch Oscillations of a Quantum Gas in a "Beat-Note" Superlattice. PHYSICAL REVIEW LETTERS 2021; 127:020601. [PMID: 34296908 DOI: 10.1103/physrevlett.127.020601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 03/17/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
We report the experimental realization of a new kind of optical lattice for ultracold atoms where arbitrarily large separation between the sites can be achieved without renouncing to the stability of ordinary lattices. Two collinear lasers, with slightly different commensurate wavelengths and retroreflected on a mirror, generate a superlattice potential with a periodic "beat-note" profile where the regions with large amplitude modulation provide the effective potential minima for the atoms. To prove the analogy with a standard large spacing optical lattice we study Bloch oscillations of a Bose Einstein condensate with negligible interactions in the presence of a small force. The observed dynamics between sites separated by ten microns for times exceeding one second proves the high stability of the potential. This novel lattice is the ideal candidate for the coherent manipulation of atomic samples at large spatial separations and might find direct application in atom-based technologies like trapped-atom interferometers and quantum simulators.
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Affiliation(s)
- L Masi
- CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
| | - T Petrucciani
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
| | - G Ferioli
- CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
| | - G Semeghini
- CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
| | - G Modugno
- CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
| | - M Inguscio
- CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Department of Engineering, Campus Bio-Medico University of Rome, 00128 Rome, Italy
| | - M Fattori
- CNR Istituto Nazionale Ottica, 50019 Sesto Fiorentino, Italy
- European Laboratory for Nonlinear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
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11
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Miles C, Bohrdt A, Wu R, Chiu C, Xu M, Ji G, Greiner M, Weinberger KQ, Demler E, Kim EA. Correlator convolutional neural networks as an interpretable architecture for image-like quantum matter data. Nat Commun 2021; 12:3905. [PMID: 34162847 PMCID: PMC8222395 DOI: 10.1038/s41467-021-23952-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/27/2021] [Indexed: 11/09/2022] Open
Abstract
Image-like data from quantum systems promises to offer greater insight into the physics of correlated quantum matter. However, the traditional framework of condensed matter physics lacks principled approaches for analyzing such data. Machine learning models are a powerful theoretical tool for analyzing image-like data including many-body snapshots from quantum simulators. Recently, they have successfully distinguished between simulated snapshots that are indistinguishable from one and two point correlation functions. Thus far, the complexity of these models has inhibited new physical insights from such approaches. Here, we develop a set of nonlinearities for use in a neural network architecture that discovers features in the data which are directly interpretable in terms of physical observables. Applied to simulated snapshots produced by two candidate theories approximating the doped Fermi-Hubbard model, we uncover that the key distinguishing features are fourth-order spin-charge correlators. Our approach lends itself well to the construction of simple, versatile, end-to-end interpretable architectures, thus paving the way for new physical insights from machine learning studies of experimental and numerical data.
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Affiliation(s)
- Cole Miles
- Department of Physics, Cornell University, Ithaca, NY, USA
| | - Annabelle Bohrdt
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Physics and Institute for Advanced Study, Technical University of Munich, Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), München, Germany
| | - Ruihan Wu
- Department of Computer Science, Cornell University, Ithaca, NY, USA
| | - Christie Chiu
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Electrical Engineering, Princeton University, Princeton, NJ, USA
- Princeton Center for Complex Materials, Princeton University, Princeton, NJ, USA
| | - Muqing Xu
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Geoffrey Ji
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Markus Greiner
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Eugene Demler
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Eun-Ah Kim
- Department of Physics, Cornell University, Ithaca, NY, USA.
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12
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Grusdt F, Pollet L. Z_{2} Parton Phases in the Mixed-Dimensional t-J_{z} Model. PHYSICAL REVIEW LETTERS 2020; 125:256401. [PMID: 33416402 DOI: 10.1103/physrevlett.125.256401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
We study the interplay of spin and charge degrees of freedom in a doped Ising antiferromagnet, where the motion of charges is restricted to one dimension. The phase diagram of this mixed-dimensional t-J_{z} model can be understood in terms of spinless chargons coupled to a Z_{2} lattice gauge field. The antiferromagnetic couplings give rise to interactions between Z_{2} electric field lines which, in turn, lead to a robust stripe phase at low temperatures. At higher temperatures, a confined meson-gas phase is found for low doping whereas at higher doping values, a robust deconfined chargon-gas phase is seen, which features hidden antiferromagnetic order. We confirm these phases in quantum Monte Carlo simulations. Our model can be implemented and its phases detected with existing technology in ultracold atom experiments. The critical temperature for stripe formation with a sufficiently high hole concentration is around the spin-exchange energy J_{z}, i.e., well within reach of current experiments.
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Affiliation(s)
- Fabian Grusdt
- Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, Theresienstr. 37, München D-80333, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799 München, Germany
| | - Lode Pollet
- Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, Theresienstr. 37, München D-80333, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799 München, Germany
- Wilczek Quantum Center, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
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13
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Gao H, Coulthard JR, Jaksch D, Mur-Petit J. Anomalous Spin-Charge Separation in a Driven Hubbard System. PHYSICAL REVIEW LETTERS 2020; 125:195301. [PMID: 33216562 DOI: 10.1103/physrevlett.125.195301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
Spin-charge separation (SCS) is a striking manifestation of strong correlations in low-dimensional quantum systems, whereby a fermion splits into separate spin and charge excitations that travel at different speeds. Here, we demonstrate that periodic driving enables control over SCS in a Hubbard system near half filling. In one dimension, we predict analytically an exotic regime where charge travels slower than spin and can even become "frozen," in agreement with numerical calculations. In two dimensions, the driving slows both charge and spin and leads to complex interferences between single-particle and pair-hopping processes.
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Affiliation(s)
- Hongmin Gao
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Jonathan R Coulthard
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Dieter Jaksch
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore
| | - Jordi Mur-Petit
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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14
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Koepsell J, Hirthe S, Bourgund D, Sompet P, Vijayan J, Salomon G, Gross C, Bloch I. Robust Bilayer Charge Pumping for Spin- and Density-Resolved Quantum Gas Microscopy. PHYSICAL REVIEW LETTERS 2020; 125:010403. [PMID: 32678648 DOI: 10.1103/physrevlett.125.010403] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Quantum gas microscopy has emerged as a powerful new way to probe quantum many-body systems at the microscopic level. However, layered or efficient spin-resolved readout methods have remained scarce as they impose strong demands on the specific atomic species and constrain the simulated lattice geometry and size. Here we present a novel high-fidelity bilayer readout, which can be used for full spin- and density-resolved quantum gas microscopy of two-dimensional systems with arbitrary geometry. Our technique makes use of an initial Stern-Gerlach splitting into adjacent layers of a highly stable vertical superlattice and subsequent charge pumping to separate the layers by 21 μm. This separation enables independent high-resolution images of each layer. We benchmark our method by spin- and density-resolving two-dimensional Fermi-Hubbard systems. Our technique furthermore enables the access to advanced entropy engineering schemes, spectroscopic methods, or the realization of tunable bilayer systems.
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Affiliation(s)
- Joannis Koepsell
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Sarah Hirthe
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Dominik Bourgund
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Pimonpan Sompet
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Jayadev Vijayan
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Guillaume Salomon
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Christian Gross
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
- Physikalisches Institut, Eberhard Karls Universität Tübingen, 72076 Tübingen, Germany
| | - Immanuel Bloch
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
- Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 München, Germany
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15
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Edri H, Raz B, Matzliah N, Davidson N, Ozeri R. Observation of Spin-Spin Fermion-Mediated Interactions between Ultracold Bosons. PHYSICAL REVIEW LETTERS 2020; 124:163401. [PMID: 32383926 DOI: 10.1103/physrevlett.124.163401] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/03/2020] [Indexed: 06/11/2023]
Abstract
Interactions in an ultracold boson-fermion mixture are often manifested by elastic collisions. In a mixture of a condensed Bose gas (BEC) and spin polarized degenerate Fermi gas (DFG), fermions can mediate spin-spin interactions between bosons, leading to an effective long-range magnetic interaction analogous to Ruderman-Kittel-Kasuya-Yosida [Phys. Rev. 96, 99 (1954); Prog. Theor. Phys. 16, 45 (1956); Phys. Rev. 106, 893 (1957)] interaction in solids. We used Ramsey spectroscopy of the hyperfine clock transition in a ^{87}Rb BEC to measure the interaction mediated by a ^{40}K DFG. By controlling the boson density we isolated the effect of mediated interactions from mean-field frequency shifts due to direct collision with fermions. We measured an increase of boson spin-spin interaction by a factor of η=1.45±0.05^{stat}±0.13^{syst} in the presence of the DFG, providing clear evidence of spin-spin fermion mediated interaction. Decoherence in our system was dominated by inhomogeneous boson density shift, which increased significantly in the presence of the DFG, again indicating mediated interactions. We also measured a frequency shift due to boson-fermion interactions in accordance with a scattering length difference of a_{bf_{2}}-a_{bf_{1}}=-5.36±0.44^{stat}±1.43^{syst}a_{0} between the clock-transition states, a first measurement beyond the low-energy elastic approximation [R. Côté, A. Dalgarno, H. Wang, and W. C. Stwalley, Phys. Rev. A 57, R4118 (1998); A. Dalgarno and M. Rudge, Proc. R. Soc. A 286, 519 (1965)] in this mixture. This interaction can be tuned with a future use of a boson-fermion Feshbach resonance. Fermion-mediated interactions can potentially give rise to interesting new magnetic phases and extend the Bose-Hubbard model when the atoms are placed in an optical lattice.
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Affiliation(s)
- Hagai Edri
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Boaz Raz
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Noam Matzliah
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nir Davidson
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Roee Ozeri
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
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16
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Dehollain JP, Mukhopadhyay U, Michal VP, Wang Y, Wunsch B, Reichl C, Wegscheider W, Rudner MS, Demler E, Vandersypen LMK. Nagaoka ferromagnetism observed in a quantum dot plaquette. Nature 2020; 579:528-533. [PMID: 32123352 DOI: 10.1038/s41586-020-2051-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 01/08/2020] [Indexed: 11/09/2022]
Abstract
Engineered, highly controllable quantum systems are promising simulators of emergent physics beyond the simulation capabilities of classical computers1. An important problem in many-body physics is itinerant magnetism, which originates purely from long-range interactions of free electrons and whose existence in real systems has been debated for decades2,3. Here we use a quantum simulator consisting of a four-electron-site square plaquette of quantum dots4 to demonstrate Nagaoka ferromagnetism5. This form of itinerant magnetism has been rigorously studied theoretically6-9 but has remained unattainable in experiments. We load the plaquette with three electrons and demonstrate the predicted emergence of spontaneous ferromagnetic correlations through pairwise measurements of spin. We find that the ferromagnetic ground state is remarkably robust to engineered disorder in the on-site potentials and we can induce a transition to the low-spin state by changing the plaquette topology to an open chain. This demonstration of Nagaoka ferromagnetism highlights that quantum simulators can be used to study physical phenomena that have not yet been observed in any experimental system. The work also constitutes an important step towards large-scale quantum dot simulators of correlated electron systems.
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Affiliation(s)
- J P Dehollain
- QuTech, TU Delft, Delft, The Netherlands.,Kavli Institute of Nanoscience, TU Delft, Delft, The Netherlands.,School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - U Mukhopadhyay
- QuTech, TU Delft, Delft, The Netherlands.,Kavli Institute of Nanoscience, TU Delft, Delft, The Netherlands
| | - V P Michal
- QuTech, TU Delft, Delft, The Netherlands.,Kavli Institute of Nanoscience, TU Delft, Delft, The Netherlands
| | - Y Wang
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - B Wunsch
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - C Reichl
- Solid State Physics Laboratory, ETH Zürich, Zürich, Switzerland
| | - W Wegscheider
- Solid State Physics Laboratory, ETH Zürich, Zürich, Switzerland
| | - M S Rudner
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.,Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - E Demler
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - L M K Vandersypen
- QuTech, TU Delft, Delft, The Netherlands. .,Kavli Institute of Nanoscience, TU Delft, Delft, The Netherlands.
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17
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Vijayan J, Sompet P, Salomon G, Koepsell J, Hirthe S, Bohrdt A, Grusdt F, Bloch I, Gross C. Time-resolved observation of spin-charge deconfinement in fermionic Hubbard chains. Science 2020; 367:186-189. [DOI: 10.1126/science.aay2354] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/14/2019] [Indexed: 11/02/2022]
Abstract
Elementary particles carry several quantum numbers, such as charge and spin. However, in an ensemble of strongly interacting particles, the emerging degrees of freedom can fundamentally differ from those of the individual constituents. For example, one-dimensional systems are described by independent quasiparticles carrying either spin (spinon) or charge (holon). Here, we report on the dynamical deconfinement of spin and charge excitations in real space after the removal of a particle in Fermi-Hubbard chains of ultracold atoms. Using space- and time-resolved quantum gas microscopy, we tracked the evolution of the excitations through their signatures in spin and charge correlations. By evaluating multipoint correlators, we quantified the spatial separation of the excitations in the context of fractionalization into single spinons and holons at finite temperatures.
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Affiliation(s)
- Jayadev Vijayan
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Pimonpan Sompet
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Guillaume Salomon
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Joannis Koepsell
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Sarah Hirthe
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Annabelle Bohrdt
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
- Department of Physics and Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany
| | - Fabian Grusdt
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
- Department of Physics and Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany
- Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 München, Germany
| | - Immanuel Bloch
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
- Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstraße 4, 80799 München, Germany
| | - Christian Gross
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
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18
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Koepsell J, Vijayan J, Sompet P, Grusdt F, Hilker TA, Demler E, Salomon G, Bloch I, Gross C. Imaging magnetic polarons in the doped Fermi–Hubbard model. Nature 2019; 572:358-362. [DOI: 10.1038/s41586-019-1463-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 06/10/2019] [Indexed: 11/09/2022]
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19
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Schauss P. Polarons leave a trace. Science 2019; 365:218. [DOI: 10.1126/science.aax6486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Spin and charge interplay leads to stringlike excitations in the 2D Hubbard model
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Affiliation(s)
- Peter Schauss
- Department of Physics, University of Virginia, Charlottesville, VA 22904-4714, USA
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