Phase diagram of the extended hubbard model with pair hopping interaction (original) (raw)

2002, The European Physical Journal B-Condensed …

A one-dimensional model of interacting electrons with on-site U , nearest-neighbor V , and pairhopping interaction W is studied at half-filling using the continuum limit field theory approach. The ground state phase diagram is obtained for a wide range of coupling constants. In addition to the insulating spin-and charge-density wave phases for large U and V , respectively, we identify bond-located ordered phases corresponding to an enhanced Peierls instability in the system for W < 0, |U − 2V | < |2W |, and to a staggered magnetization located on bonds between sites for W > 0, |U − 2V | < W. The general ground state phase diagram including insulating, metallic, and superconducting phases is discussed. A transition to the ηπ-superconducting phase at |U − 2V | ≪ 2t ≤ W is briefly discussed.