The effects of the electron–phonon interaction on a Mott insulator

Abstract Using the dynamical mean field theory we show that an electron–phonon interaction can revert the energetic balance between the metallic state and the Mott insulator in the density-driven metal-insulator transition at zero temperature. We present results for the Hubbard–Holstein model where the Mott ground state is found for sufficiently high values of the electron–phonon coupling but still not in the polaronic regime.