Dimerization in a half-filled one-dimensional extended Hubbard model

We use a density-matrix renormalization group method to study quantitatively the phase diagram of a one-dimensional extended Hubbard model at half filling by investigating the correlation functions and structure factors. We confirmed the existence of a novel narrow region with long-range bond-order-wave order that was highly controversial recently between the charge-density-wave phase and Mott insulator phase. We determined accurately the position of the bicritical point U(b)similar or equal to7.2t, V(b)similar or equal to3.746t, which is quite different from previous studies.