Ground state properties of the Holstein-Hubbard model

Tadahiro Miyao

Published 2016-10-27Version 1

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 ferromagnetism whenever the electron-phonon interaction is not so strong. In addition, the ferrimagnetic 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.