Electronic excitation spectra of the Emery model

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.47.8947· OSTI ID:6652813

Unger, P; Fulde, P ^[1]

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1. Max-Planck-Institut fuer Festkoerperforschung, D-7000 Stuttgart 80 (Germany)

We calculate the photoemission and inverse photoemission spectra of holes in copper-oxygen planes, the characteristic structural unit of high-temperature superconductors. The computations are based on the extended Hubbard or Emery model in the limit of infinitely strong Coulomb repulsion [ital U][sub [ital d]] on copper sites. In order to evaluate the corresponding one-particle correlation functions the projection technique is applied, which is especially suitable for strongly correlated systems. Thereby the hole dynamics is restricted to a subspace of relevant operators, within which it can be treated exactly. In contrast to independent-particle approximations the excitation spectra show an energy gap at half-filling, which disappears when the system is doped with additional holes. Besides the insulator-to-metal transition the strong correlations lead also to a significant shift of spectral weight to states close to the Fermi energy when the hole concentration increases. Our results are in good agreement with the ones of exact diagonalization studies of the (CuO[sub 2])[sub 4] cluster with periodic boundary conditions.

• OSTI ID: 6652813
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 47:14; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COPPER COMPOUNDS
CORRELATION FUNCTIONS
COULOMB FIELD
CRYSTAL MODELS
CUPRATES
ELECTRIC FIELDS
ELECTRONIC STRUCTURE
EMERY OPERATION
ENERGY LEVELS
EXCITED STATES
EXPLOSIONS
FUNCTIONS
HIGH-TC SUPERCONDUCTORS
HOLES
HUBBARD MODEL
MATHEMATICAL MODELS
NUCLEAR EXPLOSIONS
OXYGEN COMPOUNDS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
UNDERGROUND EXPLOSIONS