Exact Solution of a Hubbard Chain with Bond-Charge Interaction

Exact solution of a Hubbard chain with bond-charge interaction.

We obtain the exact solution of a general Hubbard chain with kinetic energy t, bond-charge interaction X and on-site interaction U with the only restriction t = X. At zero temperature and half filling, the model exhibits a Mott transition at U = 4t. In the metallic phase and near half filling, superconducting states are part of the degenerate ground state and are favored for small U if the syst...

Bond-charge interaction in the extended Hubbard chain.

We study the effects of bond-charge interaction (or correlated hopping) on the properties of the extended (i.e., with both on-site (U) and nearest-neighbor (V ) repulsions) Hubbard model in one dimension at half-filling. Energy gaps and correlation functions are calculated by Lanczos diagonalization on finite systems. We find that, irrespective of the sign of the bond-charge interaction, X, the...

Finite-temperature properties of the Hubbard chain with bond-charge interaction

Superconductivity and Topological Numbers in the Hubbard Chain with Bond-Charge Interaction

We determine the quantum phase diagram of the Hubbard chain with electron-hole symmetric correlated hopping at 1/2and 1/4-filling using geometric concepts and continuum limit field theory. The long distance behavior of various correlation functions show a very rich phase diagram with several insulating, metallic, and superconducting phases, which might be relevant to (TMTSF)2X compounds. The cl...

Hubbard model with bond-charge interaction on a triangular lattice: a renormalization group study

We have studied the Hubbard model with bond-charge interaction on a triangular lattice for a half-filled band. At the point of particle-hole symmetry the model could be analyzed in detail in two opposite regimes of the parameter space. Using a real space renormalization group we calculate the ground state energy and the local moment over the whole parameter space. The RG results obey the exact ...