High-energy anomalies in covalent high-T sub(c) cuprates with large Hubbard U sub(d) on copper

• Published in: Physica. B, Condensed matter Vol. 460; pp. 141 - 146
• Main Authors: Barisic, O S, Barisic, S
• Format: Journal Article
• Language: English
• Published: 01.03.2015
• Subjects: Asymptotic properties; Charge; Condensed matter; Copper; COPPER OXIDE; Covalence; Cuprates; DAMPING PROPERTIES; Gages; Invariants; PROPERTIES
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2014.11.057

A large U sub(d) theory is constructed for the metallic state of high-T sub(c) cuprates. The Emery three-band model, extended with O sub(x)-O sub(y) hopping t sub(pp), and with Ud arrow right [infinity], is mapped on slave fermions. The Dyson time-dependent diagrammatic theory in terms of the Cu-O hopping t sub(pd), starting from the nondegenerate unperturbed ground state, is translationally and asymptotically locally gauge invariant. The small parameter of the theory is the average hole occupation of Cu sites n sub(d). The lowest order of the theory generates the single particle propagators of the hybridized pdp- and dpd-fermions with the exact covalent three band structure. The leading many-body effect is band narrowing, accompanied by Landau-like damping of the single particle propagation, due to incoherent local charge Cu-O fluctuations. The corresponding continuum is found below and above the Fermi level.