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Phase diagram of the one-dimensional extended attractive Hubbard model for large nearest-neighbor repulsion

A. A. Aligia
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Abstract

We consider the extended Hubbard model with attractive on-site interaction U and nearest-neighbor repulsions V. We construct an effective Hamiltonian H_{eff} for hopping t<<V and arbitrary U<0. Retaining the most important terms, H_{eff} can be mapped onto two XXZ models, solved by the Bethe ansatz. The quantum phase diagram shows two Luttinger liquid phases and a region of phase separation between them. For density n<0.422 and U<-4, singlet superconducting correlations dominate at large distances. For some parameters, the results are in qualitative agreement with experiments in BaKBiO.

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A. A. Aligia. 1999-11-24. Phase diagram of the one-dimensional extended attractive Hubbard model for large nearest-neighbor repulsion. https://doi.org/10.1103/physrevb.61.7028

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