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arXiv:0806.2810 · Physical Review B

Superconductivity in a Hubbard-Fröhlich model and in cuprates

Thomas M. Hardy, J. P. Hague, John H. Samson, A. S. Alexandrov

Published Jun 2, 2009• 51 citations
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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 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 Fr\"ohlich electron-phonon interaction.

DOI
10.1103/physrevb.79.212501

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