Comparison of Effective Models for CuO2 Layers in Oxide Superconductors

  • A. Ramšak
  • P. Prelovšek
Part of the NATO ASI Series book series (NSSB, volume 218)

Abstract

Several effective models, as derived from a general two-band Hubbard model for CuO2 layers in oxide superconductors are studied. In particular we compare the Hubbard model with the hole-spin models (unsymmetrized and symmetrized) and a generalized effectice single-band (t-J) model.1 Our exact diagonalization results for a finite CuO2 chain of 4 cells show that spectral properties of a single mobile quasiparticle in a general Hubbard model can be well reproduced by reduced effective models. This remains valid even in the mixed valence regime, where the straightforward derivation of the hole-spin model is not possible due to the breakdown of the perturbation expression using hopping parameter in the Hubbard model as a small parameter.

Reference

  1. A. Ramšak and P. Prelovšek, Phys. Rev. B 40, 2239 (1989).ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1990

Authors and Affiliations

  • A. Ramšak
    • 1
  • P. Prelovšek
    • 1
  1. 1.J. Stefan Institute and Department of PhysicsUniversity of LjubljanaLjubljanaYugoslavia

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