Optimizing superconductivity in the three-band Hubbard model

We explore the phase diagram of the three-band Hubbard model for high-T_c cuprates using Cluster Dynamical Mean Field Theory at zero temperature with an exact diagonalization solver. Our goal is to maximize the superconducting order parameter and identify the model characteristics that most enhance superconductivity. We start with realistic values of the band parameters from Weber et al [1]. We observe that the order parameter at optimal doping is monotonously related to the oxygen doping and the charge-transfer gap. We also find a marked correlation of the order parameter at optimal doping with the occupation of the upper Hubbard band. We report on the correlation of the maximum order parameter with other characteristics of the model, such as the spin susceptibility etc.

[1] Weber et al, Europhysics letters, 100 (2012) 37001