Pairing of three holes in a one-dimensional lattice within the generalized Hubbard model

Abstract

Within the generalized Hubbard model, the pairing problem of a system of three correlated holes in a one-dimensional lattice is studied. This study has been done by extending the previously reported real-space mapping method [1], in order to incorporate the bond-charge interactions, The system is solved in a non-perturbative way for different values of the hopping parameters as well as the on-site (U) and nearest-neighbor (V) interaction. It is found an electron-hole pairing asymmetry, contrary to that for a bipartite lattice We also obtained, for some values of the Hubbard parameters, that the hole-singlet pairing is not always stronger than the electron case, in contrast with that for a non-bipartite lattice like the triangular one.