Suppression of d-wave superconductivity in the checkerboard Hubbard model

Using a dynamical cluster quantum Monte Carlo approximation, we investigate the d-wave superconducting transition temperature T_c in the doped two-dimensional repulsive Hubbard model with a weak inhomogeneity. The inhomogeneity is introduced in the hoppings t^′ and t in the form of a checkerboard pattern where t is the hopping within a 2×2 plaquette, and t^′ is the hopping between the plaquettes. We find inhomogeneity suppresses T_c. The characteristic spin excitation energy and the strength of d-wave pairing interaction decrease with decreasing T_c, suggesting a strong correlation between these quantities.