Bond-located phases driven by exchange interaction in the one-dimensional t-U-V-J model

The one-dimensional half-filled extended Hubbard model with on-site repulsion (U) and nearest-neighbor interactions including Coulomb repulsion (V) and exchange (J) is studied in the weak-coupling regime. We present a theoretical argument for the occurrence of bond-located phases. The bond-charge-density-wave (BCDW) is realized for J > 0 and bond-spin-density-wave (BSDW) occurs for J < 0. (C) 2011 Elsevier B.V. All rights reserved.