title: Phase separation close to the density-driven Mott transition in the Hubbard-Holstein model.
abstract: The density-driven Mott transition is studied by means of dynamical mean-field theory in the Hubbard-Holstein model, where the Hubbard term leading to the Mott transition is supplemented by an electron-phonon (e-ph) term. We show that an intermediate e-ph coupling leads to a first-order transition at T=0, which is accompanied by a phase separation between a metal and an insulator. The compressibility in the metallic phase is substantially enhanced. At quite larger values of the coupling, a polaronic phase emerges coexisting with a nonpolaronic metal.
authors.affiliation: Enrico Fermi Center, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Capone
authors.forename: G
authors.initials: G
authors.lastname: Sangiovanni
authors.forename: C
authors.initials: C
authors.lastname: Castellani
authors.forename: C
authors.initials: C
authors.lastname: Di Castro
authors.forename: M
authors.initials: M
authors.lastname: Grilli