The fully symmetric Cu-O clusters with a central Cu have two-hole singlet eigenstates which are not affected by the on-site repulsion. These pairs become bound states if the number of holes in the cluster is appropriate; moreover, the quantization at half-integer values of a magnetic test flux is consistent with a superconducting pattern. To investigate the mechanism of pairing, we study the symmetric clusters with less than or equal to 21 atoms and four holes by exact diagonalization. Further, by the diagrammatic expansion of the ground-state energy and of the scattering amplitude, we obtain the spin-flip diagrams for the effective interaction, which is attractive for singlets and repulsive for triplets. A criterion for pairing in cluster calculations is thereby obtained.

Cini M., B.A. (1997). Cluster approach to the three-band Hubbard model of the Cu-O plane: Superconducting pairs. PHYSICAL REVIEW. B, CONDENSED MATTER, 56(22), 14711-14716.

Cluster approach to the three-band Hubbard model of the Cu-O plane: Superconducting pairs

CINI, MICHELE;BALZAROTTI, ADALBERTO
1997

Abstract

The fully symmetric Cu-O clusters with a central Cu have two-hole singlet eigenstates which are not affected by the on-site repulsion. These pairs become bound states if the number of holes in the cluster is appropriate; moreover, the quantization at half-integer values of a magnetic test flux is consistent with a superconducting pattern. To investigate the mechanism of pairing, we study the symmetric clusters with less than or equal to 21 atoms and four holes by exact diagonalization. Further, by the diagrammatic expansion of the ground-state energy and of the scattering amplitude, we obtain the spin-flip diagrams for the effective interaction, which is attractive for singlets and repulsive for triplets. A criterion for pairing in cluster calculations is thereby obtained.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore FIS/03 - Fisica della Materia
English
HIGH-TEMPERATURE SUPERCONDUCTIVITY; TWO-DIMENSIONAL CUO2; CHARGE INSTABILITIES; MECHANISM; SYMMETRY; OXIDES
Cini M., B.A. (1997). Cluster approach to the three-band Hubbard model of the Cu-O plane: Superconducting pairs. PHYSICAL REVIEW. B, CONDENSED MATTER, 56(22), 14711-14716.
Cini, M; Balzarotti, A
Articolo su rivista
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/58667
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact