Ground State Properties of the Holstein–Hubbard Model

Abstract

We study the ground state properties of the Holstein–Hubbard model on some bipartite lattices at half-filling; The ground state is proved to exhibit ferrimagnetism whenever the electron–phonon interaction is not so strong. In addition, the antiferromagnetic long-range order is shown to exist in the ground state. In contrast to this, we prove the absence of the long-range charge order.