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Lu X, Chen F, Zhu W, Sheng DN, Gong SS. Emergent Superconductivity and Competing Charge Orders in Hole-Doped Square-Lattice t-J Model. Phys Rev Lett 2024; 132:066002. [PMID: 38394594 DOI: 10.1103/physrevlett.132.066002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 09/08/2023] [Accepted: 01/09/2024] [Indexed: 02/25/2024]
Abstract
The square-lattice Hubbard and closely related t-J models are considered as basic paradigms for understanding strong correlation effects and unconventional superconductivity (SC). Recent large-scale density matrix renormalization group simulations on the extended t-J model have identified d-wave SC on the electron-doped side (with the next-nearest-neighbor hopping t_{2}>0) but a dominant charge density wave (CDW) order on the hole-doped side (t_{2}<0), which is inconsistent with the SC of hole-doped cuprate compounds. We re-examine the ground-state phase diagram of the extended t-J model by employing the state-of-the-art density matrix renormalization group calculations with much enhanced bond dimensions, allowing more accurate determination of the ground state. On six-leg cylinders, while different CDW phases are identified on the hole-doped side for the doping range δ=1/16-1/8, a SC phase emerges at a lower doping regime, with algebraically decaying pairing correlations and d-wave symmetry. On the wider eight-leg systems, the d-wave SC also emerges on the hole-doped side at the optimal 1/8 doping, demonstrating the winning of SC over CDW by increasing the system width. Our results not only suggest a new path to SC in general t-J model through weakening the competing charge orders, but also provide a unified understanding on the SC of both hole- and electron-doped cuprate superconductors.
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Affiliation(s)
- Xin Lu
- School of Physics, Beihang University, Beijing 100191, China
| | - Feng Chen
- Department of Physics and Astronomy, California State University Northridge, Northridge, California 91330, USA
| | - W Zhu
- School of Science, Westlake University, Hangzhou 310024, China; Institute of Natural Sciences, Westlake Institute of Advanced Study, Hangzhou 310024, China; and Key Laboratory for Quantum Materials of Zhejiang Province, Westlake University, Hangzhou 310024, China
| | - D N Sheng
- Department of Physics and Astronomy, California State University Northridge, Northridge, California 91330, USA
| | - Shou-Shu Gong
- School of Physical Sciences, Great Bay University, Dongguan 523000, China and Great Bay Institute for Advanced Study, Dongguan 523000, China
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Gong S, Zhu W, Sheng DN. Robust d-Wave Superconductivity in the Square-Lattice t-J Model. Phys Rev Lett 2021; 127:097003. [PMID: 34506200 DOI: 10.1103/physrevlett.127.097003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Unravelling competing orders emergent in doped Mott insulators and their interplay with unconventional superconductivity is one of the major challenges in condensed matter physics. To explore the possible superconducting state in a doped Mott insulator, we study the square-lattice t-J model with both the nearest-neighbor and next-nearest-neighbor electron hoppings and spin interactions. By using the state-of-the-art density matrix renormalization group calculation with imposing charge U(1) and spin SU(2) symmetries on the six-leg cylinders, we establish a quantum phase diagram including three phases: a stripe charge density wave phase, a superconducting phase without static charge order, and a superconducting phase coexistent with a weak charge stripe order. Crucially, we demonstrate that the superconducting phase has a power-law pairing correlation that decays much slower than the charge density and spin correlations, which is a quasi-1D descendant of the uniform d-wave superconductor in two dimensions. These findings reveal that enhanced charge and spin fluctuations with optimal doping is able to produce robust d-wave superconductivity in doped Mott insulators, providing a foundation for connecting theories of superconductivity to models of strongly correlated systems.
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Affiliation(s)
- Shoushu Gong
- Department of Physics, Beihang University, Beijing 100191, China
| | - W Zhu
- School of Science, Westlake University, Hangzhou 310024, China; Institute of Natural Sciences, Westlake Institute of Advanced Study, Hangzhou 310024, China; and Key Laboratory for Quantum Materials of Zhejiang Province, Westlake University, Hangzhou 310024, China
| | - D N Sheng
- Department of Physics and Astronomy, California State University Northridge, Northridge, California 91330, USA
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Huang HX, Chen J, Ren W, Gao Y, Li W, Chen Y. Insulator-metal transition and quasi-flat-band of Shastry-Sutherland lattice. J Phys Condens Matter 2019; 31:345402. [PMID: 31096201 DOI: 10.1088/1361-648x/ab2228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Insulator-metal transition is investigated self-consistently on the frustrated Shastry-Sutherland lattice in the framework of Slave-Boson mean-field theory. Due to the presence of quasi-flat band structure characteristic, the system displays a spin-density-wave (SDW) insulating phase at the weak doping levels, which is robust against frustration, and it will be transited into an SDW metallic phase at high doping levels. As further increasing the doping, the temperature or the frustration on the diagonal linking bonds, the magnetic order m will be monotonically suppressed, resulting in the appearance of a paramagnetic metallic phase. Although the Fermi surface of the SDW metallic phase may be immersed by temperature, the number of mobile charges is robust against temperature at weak doping levels.
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Affiliation(s)
- Huai-Xiang Huang
- Department of Physics and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, People's Republic of China
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Corboz P, Rice TM, Troyer M. Competing states in the t-J model: uniform D-wave state versus stripe state. Phys Rev Lett 2014; 113:046402. [PMID: 25105638 DOI: 10.1103/physrevlett.113.046402] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Variational studies of the t-J model on the square lattice based on infinite projected-entangled pair states confirm an extremely close competition between a uniform d-wave superconducting state and different stripe states. The site-centered stripe with an in-phase d-wave order has an equal or only slightly lower energy than the stripe with antiphase d-wave order. The optimal stripe filling is not constant but increases with J/t. A nematic anisotropy reduces the pairing amplitude and the energies of stripe phases are lowered relative to the uniform state with increasing nematicity.
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Affiliation(s)
- Philippe Corboz
- Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland and Institute for Theoretical Physics, University of Amsterdam, Science Park 904, Postbus 94485, 1090 GL Amsterdam, Netherlands
| | - T M Rice
- Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland
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Voo KK. Order and excitation in partially Gutzwiller projected t-t'-t"-J-U models. J Phys Condens Matter 2011; 23:495602. [PMID: 22101308 DOI: 10.1088/0953-8984/23/49/495602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Extended t-t'-t"-J-U models in which the second-nearest-neighbor hopping (t') and third-nearest-neighbor hopping (t") are included are studied using renormalized mean field theory. The models are meant to be low-energy effective models for the Hubbard models, and hence the Heisenberg exchange integral J and Hubbard repulsion U are related by J = 4t(2)/U. The trial wavefunctions for the ground states are partially Gutzwiller projected Hartree-Fock states. The Gutzwiller projection is implemented by means of a Gutzwiller approximation, and the site double occupancy d is taken as a variational parameter. It is found that a large |t'/t| narrows the band filling range that sustains antiferromagnetism (AFM) in the ground state, enhances the d-wave singlet superconductivity (dSC) in hole overdoped systems, but suppresses the dSC in electron overdoped systems. For a system that has large |t'/t| and |t"/t'|, the superconductivity (SC) at the onset of AFM in hole doped band filling is strongly suppressed. On the excitation occurring, when an electron doped system simultaneously contains SC and AFM, the system is found to have a nodeless gap at the Fermi level. Finally, the result of this study is related to experiments on the superconducting cuprates.
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Affiliation(s)
- Khee-Kyun Voo
- Department of Communication Engineering, Oriental Institute of Technology, Banqiao Area, New Taipei City 22061, Taiwan.
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Sakakibara H, Usui H, Kuroki K, Arita R, Aoki H. Two-orbital model explains the higher transition temperature of the single-layer Hg-cuprate superconductor compared to that of the La-cuprate superconductor. Phys Rev Lett 2010; 105:057003. [PMID: 20867949 DOI: 10.1103/physrevlett.105.057003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Indexed: 05/29/2023]
Abstract
In order to explore the reason why the single-layered cuprates, La(2-x)(Sr/Ba)(x)CuO4 (T(c)≃40 K) and HgBa2CuO(4+δ) (T(c)≃90 K) have such a significant difference in T(c), we study a two-orbital model that incorporates the d(z2) orbital on top of the d(x2-y2) orbital. It is found, with the fluctuation exchange approximation, that the d(z2) orbital contribution to the Fermi surface, which is stronger in the La system, works against d-wave superconductivity, thereby dominating over the effect of the Fermi surface shape. The result resolves the long-standing contradiction between the theoretical results on Hubbard-type models and the experimental material dependence of T(c) in the cuprates.
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Affiliation(s)
- Hirofumi Sakakibara
- Department of Applied Physics and Chemistry, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
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Pathak S, Shenoy VB, Randeria M, Trivedi N. Competition between antiferromagnetic and superconducting states, electron-hole doping asymmetry, and fermi-surface topology in high temperature superconductors. Phys Rev Lett 2009; 102:027002. [PMID: 19257310 DOI: 10.1103/physrevlett.102.027002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Indexed: 05/27/2023]
Abstract
We investigate the asymmetry between electron and hole doping in a 2D Mott insulator and the resulting competition between antiferromagnetism (AFM) and d-wave superconductivity (SC), using variational Monte Carlo calculations for projected wave functions. We find that key features of the T=0 phase diagram, such as critical doping for SC-AFM coexistence and the maximum value of the SC order parameter, are determined by a single parameter eta which characterizes the topology of the "Fermi surface" at half filling defined by the bare tight-binding parameters. Our results give insight into why AFM wins for electron doping, while SC is dominant on the hole-doped side. We also suggest using band structure engineering to control the eta parameter for enhancing SC.
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Affiliation(s)
- Sandeep Pathak
- Materials Research Centre, Indian Institute of Science, Bangalore 560 012, India
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Ribeiro TC, Wen XG. New mean-field theory of the tt't''J model applied to high-T(c) superconductors. Phys Rev Lett 2005; 95:057001. [PMID: 16090908 DOI: 10.1103/physrevlett.95.057001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Indexed: 05/03/2023]
Abstract
We introduce a new mean-field approach to the tt't''J model that incorporates both electron-like quasiparticle and spinon excitations as suggested by some experiments and numerical studies. It leads to a mean-field phase diagram which is consistent with that of hole and electron doped cuprates. Moreover, it provides a framework to describe the observed evolution of the electron spectral function from the undoped insulator to the overdoped Fermi metal for both hole and electron doping. The theory also provides a new non-BCS mechanism leading to superconductivity.
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Affiliation(s)
- Tiago C Ribeiro
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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