Cellular Dynamical Mean-field Study of the One-dimensional Peierls Hubbard Model

We investigate the one-dimensional half-filled Peierls Hubbard model at zero temperature. In order to study the spectral properties of the model, we use the cellular dynamical mean-field theory employing the exact diagonalization technique as an impurity solver. The Peierls modulation makes the system a band insulator in the absence of the interaction. We calculate the density of states to examine the interplay between the Peierls modulation and the local Coulomb interaction. An increase in the Coulomb interaction is found to result in a monotonic increase of the spectral gap. The behaviors of the density of states in the Peierls Hubbard model are also discussed in comparison with those in the standard Hubbard model.