Il Nuovo Cimento D

, Volume 20, Issue 7–8, pp 1141–1146 | Cite as

Hole pairing and flux quantization in modelCu-O clusters

  • M. Cini
  • A. Balzarotti


In the three-band Hubbard model, the fully symmetric Cu-O clusters with a central Cu and appropriate hole numbers have many-body ground states in which holes are paired. Here we investigate the mechanism of pairing, focusing on clusters with ≤ 21 atoms and 4 holes. We show that spin-flip diagrams yield the effective interaction. The analysis agrees with the results of exact diagonalization and shows that singlet-triplet splitting measures the strength of the pairing interaction. Moreover, the quantization at half-integer values of a magnetic text flux is consistent with supercon-ducting pairing.

PACS 74.60

Type-II superconductivity 

PACS 31.25

Electron correlation calculations for atoms and molecules 

PACS 74.20

Theories and models of superconducting state 

PACS 01.30.Ee

Monographs and collections 


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Copyright information

© Società Italiana di Fisica 1998

Authors and Affiliations

  • M. Cini
    • 1
  • A. Balzarotti
    • 1
  1. 1.INFM, Dipartimento di FisicaUniversità di Roma II “Tor Vergata”RomaItaly

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