Pseudogap behavior in Bi{sub 2}Ca{sub 2}SrCu{sub 2}O{sub 8}: Results of the generalized dynamical mean-field approach

Journal Article · Tue May 15 00:00:00 EDT 2007 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776107050135· OSTI ID:21072474

Kuchinskii, E Z; Nekrasov, I A ^[1]; Pchelkina, Z V ^[2]

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1. Russian Academy of Sciences, Institute for Electrophysics (Russian Federation)
2. Russian Academy of Sciences, Institute for Metal Physics (Russian Federation)

Pseudogap phenomena are observed for the normal underdoped phase of different high-T{sub c} cuprates. Among others, the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8-{delta}} (Bi2212) compound is one of the most studied experimentally. To describe the pseudogap regime in Bi2212, we use a novel generalized ab initio LDA + DMFT + {sigma}{sub k} hybrid scheme. This scheme is based on the strategy of one of the most powerful computational tools for real correlated materials: the local density approximation (LDA) + dynamical mean-field theory (DMFT). Conventional LDA + DMFT equations are here supplied with an additional (momentum-dependent) self-energy {sigma}{sub k} in the spirit of our recently proposed DMFT + {sigma}{sub k} approach taking into account pseudogap fluctuations. In the present model, {sigma}{sub k} describes nonlocal correlations induced by short-range collective Heisenberg-like antiferromagnetic spin fluctuations. The effective single-impurity problem of the DMFT is solved by the numerical renormalization group (NRG) method. Material-specific model parameters for the effective x{sup 2} - y{sup 2} orbital of Cu-3d shell of the Bi2212 compound, e.g., the values of intra-and interlayer hopping integrals between different Cu sites, the local Coulomb interaction U, and the pseudogap potential {delta} were obtained within the LDA and LDA + DMFT schemes. Here, we report on the theoretical LDA + DMFT + {sigma}{sub k} quasiparticle band dispersion and damping, Fermi surface renormalization, momentum anisotropy of (quasi)static scattering, densities of states, spectral densities, and angular-resolved photoemission (ARPES) spectra, taking into account pseudogap and bilayer splitting effects for normal (slightly) underdoped Bi2212 ({delta} = 0.15). We show that LDA + DMFT + {sigma}{sub k} successfully describes strong (pseudogap) scattering close to Brillouin zone boundaries. Our calculated LDA + DMFT + {sigma}{sub k} Fermi surfaces and ARPES spectra in the presence of pseudogap fluctuations are almost insensitive to the bilayer splitting strength. However, our LDA-calculated value of bilayer splitting is rather small to describe the experimentally observed peak-dip-hump structure. The results obtained are in good semiquantitative agreement with various recent ARPES experiments.

• OSTI ID: 21072474
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 104, Issue 5; Other Information: DOI: 10.1134/S1063776107050135; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ANTIFERROMAGNETISM
APPROXIMATIONS
BISMUTH OXIDES
BRILLOUIN ZONES
CALCIUM OXIDES
COPPER OXIDES
CUPRATES
EMISSION SPECTRA
EQUATIONS
FERMI LEVEL
FLUCTUATIONS
HIGH-TC SUPERCONDUCTORS
MEAN-FIELD THEORY
PHOTOEMISSION
RENORMALIZATION
SCATTERING
SELF-ENERGY
SPECTRAL DENSITY
STRONTIUM OXIDES