Superconducting phase diagram of the paramagnetic one-band Hubbard model

TL;DR

This paper investigates how spin fluctuations induce superconductivity in the one-band Hubbard model, revealing a phase diagram sensitive to Fermi surface topology, doping, and band structure variations.

Contribution

It provides a detailed superconducting phase diagram considering higher order interactions and Fermi surface topology effects in the Hubbard model.

Findings

Superconductivity is highly sensitive to Fermi surface topology changes.

Phase boundaries between different superconducting states exhibit peculiar features.

Superconducting instability arises from higher order effective interactions in U.

Abstract

We study spin-fluctuation-mediated superconductivity in the one-band Hubbard model. Higher order effective interactions in $U$ give rise to a superconducting instability which is very sensitive to changes in the Fermi surface topology arising as a function of doping and changes in the band structure. We show the superconducting phase diagram as a function of doping and next-nearest neighbor hopping in the limit of very small Coulomb interaction strength and discuss peculiarities arising at the phase boundaries separating different superconducting domains.