Spectral function of holes in the Emery model

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

DOI:https://doi.org/10.1103/PhysRevB.48.16607· OSTI ID:5722775

Unger, P; Fulde, P ^[1]

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1. Max-Planck-Institut fuer Festkoerperforschung, 70569 Stuttgart (Germany)

We calculate the single-particle excitation spectrum of holes in the Emery model thereby extending and improving previous calculations. The system is considered at half filling ([ital n][sub [ital h]]=1, one hole per CuO[sub 2] unit) and for hole doping, where the on-site hole-hole repulsions are kept finite. A paramagnetic form of the ground state is used. For the determination of the retarded Green's functions of copper and oxygen holes, the projection technique is applied solving the resulting equations of motions self-consistently. At half filling, the excitation spectrum exhibits a charge-transfer gap bounded by Zhang-Rice singlet states and the upper Hubbard band. Upon hole doping the flat singlet band crosses the Fermi level giving rise to a large Fermi surface at a hole concentration of [ital n][sub [ital h]]=1.25. Moreover, spectral weight is shifted from the upper Hubbard band to the states near the Fermi energy. The calculated spectral densities, the singlet dispersion for the doped system, and the transfer of spectral weight are in good quantitative agreement with exact diagonalization results for 2[times]2 CuO[sub 2] cluster.

• OSTI ID: 5722775
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:22; 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
CRYSTAL MODELS
DIFFERENTIAL EQUATIONS
ELEMENTS
ENERGY LEVELS
EQUATIONS
EQUATIONS OF MOTION
FERMI LEVEL
FUNCTIONS
GREEN FUNCTION
GROUND STATES
HIGH-TC SUPERCONDUCTORS
HOLES
HUBBARD MODEL
MATHEMATICAL MODELS
METALS
NONMETALS
OXYGEN
PARTIAL DIFFERENTIAL EQUATIONS
SPECTRAL FUNCTIONS
SUPERCONDUCTORS
TRANSITION ELEMENTS