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

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.