2025/06/02 by Ye, Ming-Yong
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2506.01553
We investigate Hubbard models with bond-charge interactions on general graphs. For a Hamiltonian \(H\) of such a model, we provide the condition on its parameters under which the \(η\)-pairing method can be employed to construct its exact eigenstates. We arrive at this condition by finding that the requirement for the \(η\)-pairing state \((η^†)N |0⟩\) to be an eigenstate of \(H\) is identical to the requirement for it to be an eigenstate of a Hubbard-type Hamiltonian \(Hm\). When the condition for \((η^†)N |0⟩\) to be an eigenstate of the Hubbard-type Hamiltonian \(Hm\) is satisfied, we demonstrate that there are additional states, distinct from \((η^†)N |0⟩\), which are also exact eigenstates of \(Hm\). Our results enhance the understanding of Hubbard models on general graphs, both with and without bond-charge interactions.