Effect of Electron-Phonon Interaction on Optical Properties in One-Dimensional Mott Insulators

Interplay of strong electron correlation and electron-phonon interaction is one of important issues in the physics of low dimensional correlated electron systems. In order to understand the interplay, we examine the optical properties of the one-dimensional (1D) Hubbard-Holstein model at half-filling, by employing the dynamical density matrix renormalization group (DMRG) technique. We discuss the effect of the electron-phonon interaction on the single-particle spectral function and the optical absorption spectrum. The dynamical DMRG data are compared with experimental data of 1D copper oxide Mott insulators.