Microscopic theory of high-temperature superconductivity in strongly correlated electronic systems

TL;DR

This paper develops a microscopic theory for high-temperature superconductivity in strongly correlated systems, highlighting the role of spin fluctuations and kinematical interactions in inducing d-wave pairing.

Contribution

It derives a Dyson equation for Green functions in the Hubbard model and demonstrates that spin fluctuations can produce high-Tc d-wave superconductivity.

Findings

High-Tc d-wave pairing is driven by electron-spin fluctuation interactions.

Coulomb repulsion and electron-phonon interactions are suppressed in the pairing mechanism.

Supports the spin-fluctuation theory of high-temperature superconductivity in cuprates.

Abstract

A consistent microscopic theory of superconductivity for strongly correlated electronic systems is presented. The Dyson equation for the normal and anomalous Green functions for the projected (Hubbard) electronic operators is derived. To compare various mechanisms of pairing, the extended Hubbard model is considered where the intersite Coulomb repulsion and the electron-phonon interaction are taken into account. We obtain the $d$-wave pairing with high-$T_c$ induced by the strong kinematical interaction of electrons with spin fluctuations, while the Coulomb repulsion and the electron-phonon interaction are suppressed for the $d$-wave pairing. These results support the spin-fluctuation mechanism of high-temperature superconductivity in cuprates previously proposed in phenomenological models.