Effective single-band Hamiltonian for electron-phonon coupling in cuprate superconductors

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Journal of Superconductivity

DOI:https://doi.org/10.1007/BF00732273· OSTI ID:106846

Song, J; Annett, J F ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

The authors derive an effective single-band Hubbard type Hamiltonian for CuO{sub 2} planes. The Hamiltonian includes both electron-electron repulsion and electron-phonon coupling to oxygen vibrational modes. They start with first-principles density functional theory parameters and then map onto a single-band model. Unlike previous mappings to a single-band Hamiltonian, this work explicitly preserves the Fermi surface shape and matrix elements of the many-band Hamiltonian. The authors consider both in-plane oxygen breathing modes as well as out-of-plane tilting modes. The latter modes have a quadratic electron-phonon coupling, and are also highly anharmonic in La{sub 2}CuO{sub 4} based superconductors. The coupling to breathing modes is too small to account for high {Tc}, while the coupling to quadratic modes is much stronger even though they would be neglected in a standard Migdal-Eliashberg approach to superconductivity.

• Sponsoring Organization: USDOE
• OSTI ID: 106846
• Journal Information: Journal of Superconductivity, Journal Name: Journal of Superconductivity Journal Issue: 6 Vol. 7; ISSN JOUSEH; ISSN 0896-1107
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER OXIDES
ELECTRON-PHONON COUPLING
HIGH-TC SUPERCONDUCTORS
HUBBARD MODEL
LANTHANUM OXIDES