A self‐consistent cluster study of the Emery model

Gros, Claudius; Valentí, Roser

doi:10.1002/andp.19945060604

Cited by 17 publications

(13 citation statements)

References 34 publications

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“…In contrast, we find no PG along the diagonal direction in the strong coupling regime unless long ranged AF correlations are considered, implying no need for two different PG mechanisms in the electron doped systems. A plausible reason for the discrepancy between the DCA and CPT results is the overestimation of AF correlations in the latter approach due to finite size effects [15] on small clusters [24] and lack of self-consistency [25].…”

Section: Introduction -mentioning

confidence: 99%

Pseudogap and Antiferromagnetic Correlations in the Hubbard Model

et al. 2006

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Using the dynamical cluster approximation and quantum monte carlo we calculate the singleparticle spectra of the Hubbard model with next-nearest neighbor hopping t ′ . In the underdoped region, we find that the pseudogap along the zone diagonal in the electron doped systems is due to long range antiferromagnetic correlations. The physics in the proximity of (0, π) is dramatically influenced by t ′ and determined by the short range correlations. The effect of t ′ on the low energy ARPES spectra is weak except close to the zone edge. The short range correlations are sufficient to yield a pseudogap signal in the magnetic susceptibility, produce a concomitant gap in the singleparticle spectra near (π, π/2) but not necessarily at a location in the proximity of Fermi surface.Introduction -The normal state phase of high T c superconductors at low doping, the pseudogap (PG) region, is characterized by strong antiferromagnetic (AF) correlations and a depletion of low energy states detected by both one and two-particle measurements [1]. Whereas the d-wave superconducting phase appears to be universal in the cuprates [2,3], the PG region displays different properties in the electron and hole doped materials [4,5]. In order to further develop a theory for high T c superconductivity it is essential to have a better understanding of the asymmetry and similarities between the electron and the hole doped materials.In the hole doped cuprates the antiferromagnetism is destroyed quickly upon doping (persisting to ≈ 2% doping) [6] and the angle resolved photoemission spectra (ARPES) show well defined quasiparticles close to (π/2, π/2) in the Brillouin zone (BZ) and gap states in the proximity of (0, π) [4,7,8]. In the electron doped cuprates AF is more robust (persisting to ≈ 15% doping) [9] and the ARPES at small doping (≈ 5%) shows sharp quasiparticles at the zone edge and gap states elsewhere in the BZ [5,8]. In the Hubbard model, or the closely related t-J model, the electron-hole asymmetry can be captured by including a finite next-nearest neighbor hopping t ′ [10,11]. In this Letter we employ a reliable technique, the dynamical cluster approximation (DCA) [12,13], on relatively large clusters, to investigate the PG and single-particle spectra at small doping, the asymmetry between electron and hole-doped systems, and the role of AF correlations on the PG physics.We find that in the hole doped systems, the PG emerges in the proximity of (0, π), requires only short range correlations, and its magnitude and symmetry is strongly influenced by t ′ . In the electron doped systems, the PG emerges along the diagonal direction, as a direct consequence of AF scattering, and requires long range AF correlations, but not necessarily long range order. The hopping t ′ enhances the AF correlations in the electron doped system and produces this AF gap. With reduced temperatures, the short range AF correlations suppress the low-energy spin excitations in both electron and hole

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Section: Introduction -mentioning

confidence: 99%

Pseudogap and Antiferromagnetic Correlations in the Hubbard Model

et al. 2006

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“…In particular the DCA has been applied to study the lowenergy properties of the Hubbard model, systematically including short-to medium ranged nonlocal correlations. Both improve on the cluster perturbation theory (CPT) 14,15 , a first attempts to use finite-size calculations to obtain approximate results for the thermodynamic limit.…”

Section: Introductionmentioning

confidence: 99%

Pseudogaps in strongly correlated metals: A generalized dynamical mean-field theory approach

et al. 2005

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“…37,38 The PM Hubbard model cannot reproduce the small pocket FS centered around (/2a,/2a). 39 However, the presence of the AF order of copper atoms changes the topology of the FS drastically. The FS calculated by the AF three-band Hubbard model is shown in Figs.…”

Section: Resultsmentioning

confidence: 99%

Electronic structure, Fermi surface, and antiferromagnetism of high-Tccuprate materials and their doping dependence

Sugihara

Ikeda

Entel³

1998

Phys. Rev. B

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We determine the electronic state of the antiferromagnetic CuO 2 layer of high-T c cuprate materials on the basis of the three-band Hubbard model and derive the doping dependence of the antiferromagnetic order, electronic structure, and the Fermi surface. We solve the equation of motion for the single-electron Green's function taking into account the strong but finite Hubbard correlation and assuming the commensurate antiferromagnetic order. The result shows qualitatively correct behavior, i.e., the decline of the antiferromagnetic order along with the doping fraction of holes or electrons from the half-filled insulating phase. We also discuss the Fermi-surface structures dependent on the hole or electron doping fraction and compare these with the results of the angle-resolved photoemission spectroscopy.

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A self‐consistent cluster study of the Emery model

Cited by 17 publications

References 34 publications

Pseudogap and Antiferromagnetic Correlations in the Hubbard Model

Pseudogap and Antiferromagnetic Correlations in the Hubbard Model

Pseudogaps in strongly correlated metals: A generalized dynamical mean-field theory approach

Electronic structure, Fermi surface, and antiferromagnetism of high-Tccuprate materials and their doping dependence

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