Peculiarities of the Electronic Structure in the Triangular Lattice Hubbard Model

https://doi.org/10.1007/s10948-025-07130-3

The evolution with interaction of the electronic structure of the triangular Hubbard model, which is believed to be the parent model for describing the electronic structure of twisted bilayer dichalcogenides, is studied within the cluster perturbation theory using 13-site clusters. Local and non-local correlations are taken into account within a cluster, while the intercluster hopping is considered using perturbation theory. We obtain the evolution of the electronic structure from metal to insulator through the pseudogap state with increasing interaction. We show that this pseudogap state is characterized by the arc–like Fermi surface with maximum spectral weight located in the Γ−� directions. The energy distribution curves at the Fermi level are not characterized by a strong spectral function peak. Such momentum-dependent behavior of pseudogap suppression of spectral function is not typical for the most familiar pseudogap in doped cuprates in the