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Title: Charge-transfer and magnetic-pairing mechanisms in the extended Hubbard model of high- Tc oxides

Abstract

Charge-transfer and spin-interaction-mediated pairing is derived within a strong-coupling expansion for an extended multiband Hubbard model describing Cu-O--based superconductors. We include both intrasite ({ital U}{sub {ital d}},{ital U}{sub {ital p}}) and intersite ({ital U}{sub {ital p}{ital d}}) Coulomb repulsions. The basic carriers are oxygen-hole quasiparticles in {ital p}{sub {sigma}} orbitals. They interact via a charge-transfer mechanism driven by {ital U}{sub {ital p}{ital d}} and via a magnetic mechanism, which is due to a constructive interplay between the enhanced (by {ital U}{sub {ital p}{ital d}}) Kondo (Cu-O) exchange and the superexchange of the Cu spins. Within the BCS limit we find that {ital U}{sub {ital p}{ital d}} enhances the relative weight of {ital s} versus {ital d}-wave pairing, with the dominance of {ital s}-wave pairing for large transfer energies {Delta}={ital E}{sub {ital p}}{minus}{ital E}{sub {ital d}} and at low-to-intermediate doping. The charge-transfer-induced coupling is negligible in this large-{Delta} limit. In the small-{Delta} limit it induces a 10--20 % enhancement of the BCS {Tc}.

Authors:
; ;  [1]
  1. Physikalisches Institut, Universitaet Wuerzburg, Am Hubland, D-8700 Wuerzburg (Federal Republic of Germany)
Publication Date:
OSTI Identifier:
6359478
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter; (USA)
Additional Journal Information:
Journal Volume: 42:4; Journal ID: ISSN 0163-1829
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; HIGH-TC SUPERCONDUCTORS; MATHEMATICAL MODELS; BCS THEORY; CHARGE TRANSPORT; COPPER OXIDES; COUPLING; HOLES; KONDO EFFECT; OXYGEN; CHALCOGENIDES; COPPER COMPOUNDS; ELEMENTS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; SUPERCONDUCTORS; TRANSITION ELEMENT COMPOUNDS; 656100* - Condensed Matter Physics- Superconductivity; 360204 - Ceramics, Cermets, & Refractories- Physical Properties

Citation Formats

Wagner, J, Muramatsu, A, and Hanke, W. Charge-transfer and magnetic-pairing mechanisms in the extended Hubbard model of high- Tc oxides. United States: N. p., 1990. Web. doi:10.1103/PhysRevB.42.2200.
Wagner, J, Muramatsu, A, & Hanke, W. Charge-transfer and magnetic-pairing mechanisms in the extended Hubbard model of high- Tc oxides. United States. https://doi.org/10.1103/PhysRevB.42.2200
Wagner, J, Muramatsu, A, and Hanke, W. Wed . "Charge-transfer and magnetic-pairing mechanisms in the extended Hubbard model of high- Tc oxides". United States. https://doi.org/10.1103/PhysRevB.42.2200.
@article{osti_6359478,
title = {Charge-transfer and magnetic-pairing mechanisms in the extended Hubbard model of high- Tc oxides},
author = {Wagner, J and Muramatsu, A and Hanke, W},
abstractNote = {Charge-transfer and spin-interaction-mediated pairing is derived within a strong-coupling expansion for an extended multiband Hubbard model describing Cu-O--based superconductors. We include both intrasite ({ital U}{sub {ital d}},{ital U}{sub {ital p}}) and intersite ({ital U}{sub {ital p}{ital d}}) Coulomb repulsions. The basic carriers are oxygen-hole quasiparticles in {ital p}{sub {sigma}} orbitals. They interact via a charge-transfer mechanism driven by {ital U}{sub {ital p}{ital d}} and via a magnetic mechanism, which is due to a constructive interplay between the enhanced (by {ital U}{sub {ital p}{ital d}}) Kondo (Cu-O) exchange and the superexchange of the Cu spins. Within the BCS limit we find that {ital U}{sub {ital p}{ital d}} enhances the relative weight of {ital s} versus {ital d}-wave pairing, with the dominance of {ital s}-wave pairing for large transfer energies {Delta}={ital E}{sub {ital p}}{minus}{ital E}{sub {ital d}} and at low-to-intermediate doping. The charge-transfer-induced coupling is negligible in this large-{Delta} limit. In the small-{Delta} limit it induces a 10--20 % enhancement of the BCS {Tc}.},
doi = {10.1103/PhysRevB.42.2200},
url = {https://www.osti.gov/biblio/6359478}, journal = {Physical Review, B: Condensed Matter; (USA)},
issn = {0163-1829},
number = ,
volume = 42:4,
place = {United States},
year = {1990},
month = {8}
}