Interplay between the Pseudogap and Superconductivity in Doped Mott Insulators: a Cluster Dynamical Mean-field Theory Study

We investigate the interplay between the pseudogap state and d-wave superconductivity in the two dimensional doped Hubbard model, by employing an eight-site cluster dynamical mean-field theory method. Via tuning electron hopping parameters, the strong-coupling pseudogap in the two dimensional Hubbard model can be either enhanced or suppressed in the doped Mott insulator regime. We find that in underdoped cases, the closing of pseudogap leads to a significant enhancement of superconductivity, indicating the competition between the two in the underdoped regime. At large dopings, in contrast, suppressing pseudogap is accompanied by a concurrent decreasing of the superconducting transition temperature T_c, which can be attributed to the decreasing of antiferromagnetic correlations behind both the pseudogap and superconductivity. We elucidate this evolving pseudogap-superconductivity relationship in different doping regimes.