HARDY, T.M. ... et al, 2009. Superconductivity in a Hubbard-Frohlich model and in cuprates. Physical Review B, 79, 212501, pp.1-4.
Using the variational Monte Carlo method, we find that a relatively weak long-range electron-phonon
interaction induces a d-wave superconducting state in doped Mott-Hubbard insulators and/or strongly correlated
metals with a condensation energy significantly larger than can be obtained with Coulomb repulsion only.
Moreover, the superconductivity is shown to exist for infinite on-site Coulomb repulsion without the need for
additional mechanisms such as spin fluctuations to mediate d-wave superconductivity. We argue that our
superconducting state is robust with respect to a more intricate choice of the trial-wave function and that a
possible origin of high-temperature superconductivity lies in a proper combination of strong electron-electron
correlations with poorly screened Fröhlich electron-phonon interaction.