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arXiv · 1301.4347

On the theory of superconductivity in the extended Hubbard model: Spin-fluctuation pairing

Nikolay M. Plakida·Viktor S. Oudovenko
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Abstract

A microscopic theory of superconductivity in the extended Hubbard model which takes into account the intersite Coulomb repulsion and electron-phonon interaction is developed in the limit of strong correlations. The Dyson equation for normal and pair Green functions expressed in terms of the Hubbard operators is derived. The self-energy is obtained in the noncrossing approximation. In the normal state, antiferromagnetic short-range correlations result in the electronic spectrum with a narrow bandwidth. We calculate superconducting Tc by taking into account the pairing mediated by charge and spin fluctuations and phonons. We found the d-wave pairing with high-Tc mediated by spin fluctuations induced by the strong kinematic interaction for the Hubbard operators. Contributions to the d-wave pairing coming from the intersite Coulomb repulsion and phonons turned out to be small.

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Nikolay M. Plakida, Viktor S. Oudovenko. 2013-01-18. On the theory of superconductivity in the extended Hubbard model: Spin-fluctuation pairing. https://doi.org/10.1140/epjb/e2013-31157-6

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