Pairing phase diagram for electron-doped cuprates in the square-lattice t − U − V Hubbard model

Motivated by significant discrepancies between experimental observations of electron-doped cuprates and numerical results of the Hubbard model, we investigate the role of nearest-neighbor (NN) electron interactions V by studying the t − U − V model on square lattices. Upon doping δ = 0.153, by using constrained path quantum Monte Carlo method, we find that NN electron attraction V can notably drive an exotic p-wave spin-triplet pairing, while the NN electron repulsion V will suppress the (Formula presented.) -wave (d-wave) pairing and triggers the d_xy-wave pairing. Especially in the intermediate coupling regime, as NN repulsion increases, the intensity of d_xy-wave pairing also increases, further suppressing the presence of d-wave pairing, which may help explain the notable suppression of d-wave pairing in electron-doped cuprate superconductors. Besides the pairing phase, we also find that the NN electron attraction V has no significant effect on spin density wave (SDW) and charge density wave (CDW), but repulsion V significantly enhanced CDW and suppressed SDW. Our study suggests the t − U − V Hubbard model can serve as the minimal model to capture the essential physics of the electron-doped cuprates.