Comparison of superconducting pairing in doped cuprates and nickelates within an extended Hubbard model

Within an extended Hubbard model, we investigate the superconducting pairing behavior of infinite-layer nickelate NdNiO₂ and cuprates superconductors by using the determinant quantum Monte Carlo method. Our focus is on comparing their dominant pairing symmetries. The results indicate that the dx²-y² pairing interaction is significantly enhanced at low temperatures in both doped nickelates and cuprates, while other typical pairing symmetries are effectively suppressed, highlighting the dominance of dx²-y² pairing form. Additionally, we find that the effective pairing interaction for dx²-y² pairing in doped nickelates is slightly lower than that in doped cuprates, which may be attributed to the different degrees of Fermi surface warping caused by the third nearest hopping $t''$. Further studies show that the hole doping and interaction strength have significant effects on the dx²-y² pairing interaction within the selected parameter range. The dx²-y² pairing interaction is notably weakened when the hole doping increases, while it is significantly enhanced with increasing Coulomb interaction strength U. This comparative analysis reveals the similarities and differences in the pairing behaviors of doped nickelates and cuprates, which may provide further insights into understanding the superconducting properties of these two classes of materials.