Eur. Phys. J. B (2012) 85: 200
https://doi.org/10.1140/epjb/e2012-30309-6

Regular Article

Effect of singlet pairing hopping on the one-dimensional extended Hubbard model with spin exchange interaction

School of Physical Science and Technology, Xinjiang University, Urumqi 830046, P.R. China

^a e-mail: dinghanqinxjdx@163.com

Received: 11 April 2012
Received in final form: 4 May 2012
Published online: 18 June 2012

Abstract

The ground-state properties of the one-dimensional (1D) t-U-J model with singlet pair hopping interaction are studied in the weak-coupling regime. The analysis of the model with U(1) ⊗ SU(2) symmetry is performed using the bosonization and renormalization-group approaches. At half filling the phase diagram is shown to consist of three different insulating states corresponding to the Peierls dimerized bond-charge-density-wave (BCDW) phase, the spin-density-wave (SDW) phase and the bond-spin-density-wave (BSDW) phase, and two different superconducting states with the singlet-superconducting (SS) phase and the triplet-superconducting (TS) phase. Moreover, the SDW, BSDW and TS phases are all degenerated. The result indicates that the pair hopping interaction P has a strong effect on the ground-state properties of 1D correlated electron systems.