Van Hove excitons and high-Tcsuperconductivity. I. Excitonic superconductivity
- 13 November 1989
- journal article
- Published by IOP Publishing in Journal of Physics: Condensed Matter
- Vol. 1 (45) , 8911-8930
- https://doi.org/10.1088/0953-8984/1/45/016
Abstract
Presents a new variant of an excitonic model to explain the superconductivity in the high-Tc oxides. The carriers in the CuO2 layers are divided into two groups: heavy and light holes. The heavy holes localise into a (charge) density wave, and it is virtual excitations across the density-wave gap which pair the light holes in a superconducting state. Such a mechanism can lead to strong deviations from BCS form for the temperature dependence of the gap. Comparison with experiment suggests that the density wave is present as two-dimensional fluctuations with long-range order setting in only near or below Tc. In La2-xSrxCuO4 it is suggested that materials with x not=0 or 0.15 are two-phase mixtures.Keywords
This publication has 59 references indexed in Scilit:
- Optical measurements on oriented thin films: Lack of evidence for excitonic superconductivityPhysical Review Letters, 1987
- Observation of an oxygen isotope effect inPhysical Review Letters, 1987
- Observation of an oxygen isotope shift in the superconducting transition temperature ofPhysical Review Letters, 1987
- Nonzero isotope effect inPhysical Review Letters, 1987
- Charge transfer excitations and superconductivity in “ionic” metalsSolid State Communications, 1987
- Superconductivity in Alcaline-Earth-Substituted La 2 CuO 4 : A Theoretical ModelEurophysics Letters, 1987
- Electronic band properties and superconductivity inPhysical Review Letters, 1987
- Lattice instability and high- superconductivity inPhysical Review Letters, 1987
- Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressurePhysical Review Letters, 1987
- Possible highT c superconductivity in the Ba?La?Cu?O systemZeitschrift für Physik B Condensed Matter, 1986