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

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