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 Tc 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 Tc. The characteristic spin excitation energy and the strength of d -wave pairing interaction decrease with decreasing Tc, suggesting a strong correlation between these quantities.