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

2025/01/25 by Cao, Zhangkai, Tan, Shuning, Liu, Ji +4
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)

paper · doi:10.48550/arxiv.2502.07079

Abstract

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 (CPQMC) 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 dx2-y2-wave (d-wave) pairing and triggers the dxy-wave pairing. Especially in the intermediate coupling regime, as NN repulsion increases, the intensity of dxy-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.

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