paper

Antagonistic effects of nearest-neighbor repulsion on the superconducting pairing dynamics in the doped Mott insulator regime

arXiv:1607.02517 · doi:10.1103/PhysRevB.94.155146

Abstract

The nearest-neighbor superexchange-mediated mechanism for d_{x^2-y^2}-wave superconductivity in the one-band Hubbard model faces the challenge that nearest-neighbor Coulomb repulsion can be larger than superexchange. To answer this question, we use cellular dynamical mean-field theory (CDMFT) with a continuous-time quantum Monte Carlo solver to determine the superconducting phase diagram as a function of temperature and doping for on-site repulsion and nearest-neighbor repulsion . In the underdoped regime, increases the CDMFT superconducting transition temperature even though it decreases the superconducting order parameter at low temperature for all dopings. However, decreases in the overdoped regime. We gain insight into these paradoxical results through a detailed study of the frequency dependence of the anomalous spectral function, extracted at finite temperature via the MaxEntAux method for analytic continuation. A systematic study of dynamical positive and negative contributions to pairing reveals that even though has a high-frequency depairing contribution, it also has a low frequency pairing contribution since it can reinforce superexchange through . Retardation is thus crucial to understand pairing in doped Mott insulators, as suggested by previous zero-temperature studies. We also comment on the tendency to charge order for large and on the persistence of d-wave superconductivity over extended- or s+d-wave.

Latex, 16 pages, 8 figures

References in corpus (19)

Cited by in corpus (3)