Phase diagrams of the one-dimensional anisotropic extended Hubbard model Original Research Article

We investigate global structures of ground-state phase diagrams in a one-dimensional electron system with on-site and spin-dependent nearest-neighbor-site Coulomb interactions. We closely compare our numerical data for phase boundaries with their analytical expressions in limiting regions of interactions, and obtain a good agreement between them. On the other hand, we find non-trivial structures of phase diagrams in the intermediate-coupling region: For systems with weak easy-plain anisotropy, both bond-located spin- and charge-density-wave phases are realized. The latter contacts with the ferromagnetic phase stabilized in the strong-coupling region. When anisotropy becomes large, a direct transition between the former and ferromagnetic phase is observed.