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Temperature and filling dependence of the superconducting $π$-phase in the Penson-Kolb-Hubbard model

Fabrizio Dolcini·Arianna Montorsi
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Abstract

We investigate in the Hartree Fock approximation the temperature and filling dependence of the superconducting $π$-phase for the Penson-Kolb-Hubbard model. Due to the presence of the pair-hopping term, the phase survives for repulsive values of the on-site Coulomb interaction, exhibiting an interesting filling and temperature dependence. The structure of the self-consistent equations peculiar to the $π$-phase of the model allows to explicitly solve them for the chemical potential. The phase diagrams are shown and discussed in dimension 2 and 3. We also show that, when a next-nearest neighbours hopping term is included, the critical temperature of the superconducting region increases, and the corresponding range of filling values is shifted away from half-filling. Comparison with known exact results is also discussed.

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Fabrizio Dolcini, Arianna Montorsi. 1999-12-17. Temperature and filling dependence of the superconducting $π$-phase in the Penson-Kolb-Hubbard model. https://doi.org/10.1103/physrevb.62.2315

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