A chemist's view of chemical bonding in the mechanism of high temperature superconductivity
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | POUCHARD, Michel | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | VILLESUZANNE, Antoine | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | DEMOURGUES, Alain | |
| dc.description.abstractEn | Through a 2-dimensionnal tight-binding crystal orbital approach and a (CuO2)2 square unit cell of parameter a, we show that a Cu2+/O2- -> Cu+/O- charge transfer is likely to occur at the M($\pi/a$, $\pi/a$) point of the Brillouin zone, for O4 groups with antibonding b1g symmetry. This approach emphasises the role of oxygen-oxygen interactions in avoiding the nesting of the Fermi surface and agrees with its observed topology. At the M point of the Brillouin zone, oxygen atoms are strongly dissymmetric ("Janus" atoms) and link copper atoms with different environments (a1g vs. b1g symmetries). Further hole doping generates two situations: two holes (S=0) and/or a single hole (S=+/- 1/2) in the O4 b1g groups ($\sigma$ or $\pi$), with a possible equilibrium between them; the former can be considered as a "hole lone pair" by analogy with electron lone pairs. Mulliken-Jaffe electronegativity considerations justify the nearly zero U Hubbard parameter value. The mixing of the pair-occupied with pair-iunoccupied wave functions is realised via an electronic hamiltonian in place of the electron-phonon coupling of the pristine BCS theory. | |
| dc.language.iso | en | |
| dc.title.en | A chemist's view of chemical bonding in the mechanism of high temperature superconductivity | |
| dc.type | Document de travail - Pré-publication | |
| dc.subject.hal | Chimie/Matériaux | |
| dc.identifier.arxiv | 1707.00870 | |
| hal.identifier | hal-01593177 | |
| hal.version | 1 | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-01593177v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.au=POUCHARD,%20Michel&VILLESUZANNE,%20Antoine&DEMOURGUES,%20Alain&rft.genre=preprint |
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