Competition between Antiferromagnetism and Superconductivity in High-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>T</mml:mi><mml:mi>c</mml:mi></mml:msub></mml:math>Cuprates

Sénéchal, David; Lavertu, Pierre-Luc; Marois, M.-A.; Tremblay, A.–M. S.

doi:10.1103/physrevlett.94.156404

Cited by 232 publications

(269 citation statements)

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“…Generalizations of Dynamical Mean-Field Theory are particularly suited for the strong coupling limit, but they are also an excellent guide to the physics at weak to intermediate coupling. [33][34][35][36][37][38][39][40][41][42] , These calculations suggest that pairing is maximized at intermediate coupling, where the on-site interaction U is of order the bandwidth W = 8t. Some non-perturbative calculations based on weak coupling ideas even agree at intermediate coupling 43 with strong-coupling based approaches.…”

Section: Introductionmentioning

confidence: 99%

Resilience ofd-wave superconductivity to nearest-neighbor repulsion

et al. 2013

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Many theoretical approaches find d-wave superconductivity in the prototypical one-band Hubbard model for high-temperature superconductors. At strong-coupling (U ≥ W , where U is the on-site repulsion and W = 8t the bandwidth) pairing is controlled by the exchange energy J = 4t 2 /U . One may then surmise, ignoring retardation effects, that near-neighbor Coulomb repulsion V will destroy superconductivity when it becomes larger than J, a condition that is easily satisfied in cuprates for example. Using Cellular Dynamical Mean-Field theory with an exact diagonalization solver for the extended Hubbard model, we show that pairing at strong coupling is preserved, even when V J, as long as V U/2. While at weak coupling V always reduces the spin fluctuations and hence d-wave pairing, at strong coupling, in the underdoped regime, the increase of J = 4t 2 /(U − V ) caused by V increases binding at low frequency while the pair-breaking effect of V is pushed to high frequency. These two effects compensate in the underdoped regime, in the presence of a pseudogap. While the pseudogap competes with superconductivity, the proximity to the Mott transition that leads to the pseudogap, and retardation effects, protect d-wave superconductivity from V .

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Section: Introductionmentioning

confidence: 99%

Resilience ofd-wave superconductivity to nearest-neighbor repulsion

et al. 2013

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“…This method captures short-range correlations exactly, treats broken symmetries with a rigorous dynamical variational principle, and provides dynamical information (the spectral function). It has been recently applied with success to the broken symmetry phases in models of high-T c superconductors [14,15]: transitions between AF and dSC states were found as a function of doping, both for hole-and electron-doped materials, at roughly the correct doping levels. Let us summarize our results (see Fig.…”

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confidence: 99%

Antiferromagnetism and Superconductivity in Layered Organic Conductors: Variational Cluster Approach

Sahebsara

Sénéchal

2006

Phys. Rev. Lett.

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The κ-(ET)2X layered conductors (where ET stands for BEDT-TTF) are studied within the dimer model as a function of the diagonal hopping t ′ and Hubbard repulsion U . Antiferromagnetism and d-wave superconductivity are investigated at zero temperature using variational cluster perturbation theory (V-CPT). For large U , Néel antiferromagnetism exists for t ′ < t ′ c2 , with t ′ c2 ∼ 0.9. For fixed t ′ , as U is decreased (or pressure increased), a d x 2 −y 2 superconducting phase appears. When U is decreased further, the a dxy order takes over. There is a critical value of t ′ c1 ∼ 0.8 of t ′ beyond which the AF and dSC phases are separated by Mott disordered phase.The proximity of antiferromagnetism (AF) and d-wave superconductivity (dSC) is a central and universal feature of high-temperature superconductors, and leads naturally to the hypothesis that the mechanisms behind the two phases are intimately related. This proximity is also observed in the layered organic conductor κ-(ET) 2 Cu-[N(CN) 2 ]Cl, an antiferromagnet that transits to a superconducting phase upon applying pressure[1] (here ET stands for BEDT-TTF). Other compounds of the same family, κ-(ET) 2 Cu(NCS) 2 and κ-(ET) 2 Cu[N(CN) 2 ]Br, are superconductors with a critical temperature near 10K at ambient pressure. However, another member of this family, κ-(ET) 2 Cu 2 (CN) 3 , displays no sign of AF order, but becomes superconducting upon applying pressure [2,3]. The character of the superconductivity in these compounds is still controversial. While many experiments indicate that the SC gap has nodes (presumably d-wave), others are interpreted as favoring a nodeless gap. The literature on the subject is rich, and we refer to a recent review article[4] for references.The interplay of AF and dSC orders, common to both high-T c and κ-ET materials, cannot be fortuitous and must be a robust feature that can be captured in a simple model of these strongly correlated systems. κ-ET compounds consist of orthogonally aligned ET dimers that form conducting layers sandwiched between insulating polymerized anion layers. The simplest theoretical description of these complex compounds is the so-called dimer Hubbard model [5,6] (Fig. 1A) in which a single bonding orbital is considered on each dimer, occupied by one electron on average, with the Hamiltonianwhere c rσ (c † rσ ) creates an electron (hole) at dimer site r on a square lattice with spin projection σ, and n rσ =c † rσ c rσ is the hole number operator. rr ′ ([rr ′ ]) indicates nearest-(next-nearest)-neighbor bonds. As the ratio t ′ /t grows from 0 towards 1, Néel AF is increasingly

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“…For pure systems and spontaneous SU(2) and U(1) symmetry breaking, this concept has already been applied successfully. 53,54,61,80 B. Molecular CPA The (disorder) VCA is obtained as the cluster generalization of the atomic approximation. Likewise, within the framework of the SFT, the cluster generalization of the CPA leads to the so-called molecular CPA (M-CPA).…”

Section: A Variational Cluster Approachmentioning

confidence: 99%

Self-energy-functional theory for systems of interacting electrons with disorder

Potthoff

Balzer

2007

Phys. Rev. B

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Based on a functional-integral formalism, a generalization of the self-energy-functional theory (SFT) is proposed which is applicable to systems of interacting electrons with disorder. Similar to the pure case without disorder, a variational principle is set up which gives the physical (disorder) self-energy as a stationary point of the (averaged) grand potential. Although the resulting self-energy functional turns out to be more complicated, the formal structure of the theory can be retained since the unknown part of the functional is universal. This allows to construct nonperturbative and thermodynamically consistent approximations via searching for a stationary point on a restricted domain of the functional. The theory and the possible approximations are worked out for models with local interactions and local disorder. This results in a derivation of different mean-field approaches and various cluster extensions, including well-known concepts as the statistical dynamical mean-field theory, the molecular coherent-potential approximation and the dynamical cluster approximation. Due to the common formal framework provided by the SFT, one achieves a general systematization of dynamical approaches, i.e. approaches based on the spectrum of oneparticle excitations. New mean-field and new cluster schemes naturally appear in this framework and complement the existing ones. Their prospects for future applications are discussed.

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Competition between Antiferromagnetism and Superconductivity in High-TcCuprates

Cited by 232 publications

References 35 publications

Resilience ofd-wave superconductivity to nearest-neighbor repulsion

Resilience ofd-wave superconductivity to nearest-neighbor repulsion

Antiferromagnetism and Superconductivity in Layered Organic Conductors: Variational Cluster Approach

Self-energy-functional theory for systems of interacting electrons with disorder

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