Journal of Low Temperature Physics

, Volume 99, Issue 3–4, pp 599–601 | Cite as

Consistent 1/N-expansion for the four-slave-boson approach with an appropriate operator-ordering prescription

  • Enrico Aarrigoni
  • Giancarlo Strinati
Novel Many-body Techniques


We study the single-band Hubbard model with arbitrary on-site repulsion U within the four-slave-boson approach. We evaluate 1/N corrections to the mean-field result by properly taking into account the additional terms due to the discretized form of the coherent-state functional integral. We show how the normal-ordering prescription for the bosonic hopping operator Zi,σ introduced by Kotliar and Ruckenstein can be suitably relaxed leading to additional contributions of\(\mathcal{O}\)(1/N) to physical quantities. The free-particle result at U = 0 is then recovered for arbitrary doping even with the inclusion of fluctuations. Numerical results are shown for finite values of U.

PACS numbers

71.30.+h 05.30.−d 71.10.+x 


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    E. Arrigoni and G. C. Strinati, Phys. Rev. Lett.71, 3178 (1993).Google Scholar

Copyright information

© Plenum Publishing Corporation 1995

Authors and Affiliations

  • Enrico Aarrigoni
    • 1
  • Giancarlo Strinati
    • 2
  1. 1.Max-Planck-Institut für Physik Komplexer SystemeStuttgartGermany
  2. 2.Dipartimento di FisicaUniversità di Roma “La Sapienza”RomaItaly

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