Phase Diagram of the Extended Hubbard Model with Correlated Hopping Interaction

Abstract

A one-dimensional model of interacting electrons with on-site $U$, nearest-neighbor $V$, and correlated-hopping interaction $T^{\ast}$ 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 $T^\ast>0$, $|U-2V|<8T^\ast/π$ and to a staggered magnetization located on bonds between sites for $T^\ast<0$, $|U-2V|<8|T^\ast|/π$. The general ground state phase diagram including insulating, metallic, and superconducting phases is discussed.