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arXiv · 0806.2810

Superconductivity in a Hubbard-Froehlich Model and in cuprates

T. M. Hardy·J. P. Hague·J. H. Samson·A. S. Alexandrov
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Abstract

Using the variational Monte-Carlo method we find that a relatively weak long-range electron-phonon interaction induces a d-wave superconducting state of 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, removing the requirement for additional mechanisms such as spin fluctuations to mediate d-wave superconductivity. We argue that the superconducting state is robust with respect to a more intricate choice of the trial function and that the true origin of high-temperature superconductivity lies in a proper combination of strong electron-electron correlations with poorly screened Froehlich electron-phonon interaction.

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T. M. Hardy, J. P. Hague, J. H. Samson, A. S. Alexandrov. 2008-06-17. Superconductivity in a Hubbard-Froehlich Model and in cuprates. https://doi.org/10.1103/physrevb.79.212501

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