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Extended Hubbard Model with Unconventional Pairing in Two Dimensions

Akinori Tanaka·Masanori Yamanaka
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Abstract

We rigorously prove that an extended Hubbard model with attraction in two dimensions has an unconventional pairing ground state for any electron filling. The anisotropic spin-0 or anisotropic spin-1 pairing symmetry is realized, depending on a phase parameter characterizing the type of local attractive interactions. In both cases the ground state is unique. It is also shown that in a special case, where there are no electron hopping terms, the ground state has Ising-type Néel order at half-filling, when on-site repulsion is furthermore added. Physical applications are mentioned.

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Akinori Tanaka, Masanori Yamanaka. 2005-03-31. Extended Hubbard Model with Unconventional Pairing in Two Dimensions. https://doi.org/10.1103/physrevb.71.233102

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