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arXiv · 1709.08411

An exactly solvable BCS-Hubbard Model in arbitrary dimensions

Zewei Chen·Xiaohui Li·Tai Kai Ng
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Abstract

We introduce in this paper an exact solvable BCS-Hubbard model in arbitrary dimensions. The model describes a p-wave BCS superconductor with equal spin pairing moving on a bipartite (cubic, square etc.) lattice with on site Hubbard interaction $U$. We show that the model becomes exactly solvable for arbitrary $U$ when the BCS pairing amplitude $\Delta$ equals the hopping amplitude $t$. The nature of the solution is described in detail in this paper. The construction of the exact solution is parallel to the exactly solvable Kitaev honeycomb model for $S=1/2$ quantum spins and can be viewed as a generalization of Kitaev's construction to $S=1/2$ interacting lattice fermions. The BCS-Hubbard model discussed in this paper is just an example of a large class of exactly solvable lattice fermion models that can be constructed similarly.

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Zewei Chen, Xiaohui Li, Tai Kai Ng. 2017-09-25. An exactly solvable BCS-Hubbard Model in arbitrary dimensions. https://doi.org/10.1103/physrevlett.120.046401

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