Spin susceptibility of one-dimensional extended Hubbard model at quarter filling

摘要

The ground-state property of one-dimensional extended Hubbard model is investigated at quarter filling. By using spin-charge factorized wave function in the U -> infinity limit, the effective exchange coupling J(eff) and spin susceptibility chi are calculated as a function of nearest-neighbor Coulomb interaction V. It is found that J(eff) is suppressed by the effect of V through charge fluctuation. The results indicate these quantities have no singularities at the transition point because of the Berezinskii-Kosterlitz-Thouless-type transition of charge ordering. We also confirm the results by exact diagonalization method in the realistic parameter range. The relevance to the experiments on quasi one-dimensional organic conductor (DI-DCNQI)(2)Ag is discussed. (c) 2006 Elsevier B.V. All rights reserved.