Superconducting correlations in the one-band Hubbard model with intermediate on-site and weak attractive intersite interactions
- Laser Technnology Research Programme, Department of Physics, Indian Institute of Technology, New Delhi 110016 (India)
- Department of Physics, Amherst College, Amherst, MA (USA)
In this paper, we analyze a simple extended Hubbard model with an intermediate on-site interaction (both repulsive and attractive) and a weak intersite attractive interaction. Following Hubbard decoupling approximations and introducing Hubbard subband operators, we obtain a generalized gap function for singlet {ital s}-wave pairing that explicitly depends on the Hubbard subband energies. For the on-site repulsive-interaction case, we find that the superconductivity is not destroyed in the intermediate-interaction regime, contrary to the prediction of a Hartree-Fock mean-field treatment. The essential consequence of the on-site repulsion is the formation of the Hubbard subbands separated by the Mott-Hubbard gap, and it is within these subbands that pairing induced by the intersite interaction occurs. For the attractive on-site interaction case, the on-site pairing amplitude is found to be proportional to the bandwidth, and the gap function has contributions from both on-site and intersite pairing. The relevance of the model to high-temperature superconductivity is discussed.
- OSTI ID:
- 5830219
- Journal Information:
- Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 42:16; ISSN PRBMD; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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