Possibility of superconductivity in the repulsive Hubbard model on the Shastry-Sutherland lattice

TL;DR

This study investigates the potential for superconductivity driven by electron repulsion in the Shastry-Sutherland lattice using the Hubbard model, highlighting the importance of Fermi surface nesting over spin dimerization.

Contribution

It demonstrates that superconductivity is more likely around quarter-filling than half-filling in this lattice, emphasizing the role of Fermi surface nesting.

Findings

Superconductivity is not favored near half-filling.

Superconductivity is favored around quarter-filling.

Fermi surface nesting is more crucial than spin dimerization for superconductivity.

Abstract

Possibility of superconductivity from electron repulsion in the Shastry-Sutherland lattice, which has a spin gap at half filling, is explored with the repulsive Hubbard model in the fluctuation-exchange approximation. We find that, while superconductivity is not favored around the half-filling, superconductivity is favored around the quarter-filling. Our results suggest that the Fermi surface nesting is more important than the spin dimerization for superconductivity.