Superconducting properties of the hole-doped three-band d−p model studied with minimal-size real-space d-wave pairing operators

Abstract

The three-band d-p model is investigated by means of a variational Monte Carlo (VMC) method with the BCS-like wave-function supplemented by the Gutzwiller and Jastrow correlators. The VMC optimization leads to a d−wave superconducting state with a characteristic domelike shape of the order parameter for hole doping δ≲0.4, in good agreement with the experimental observations. Also, the off-diagonal pair-pair correlation functions, calculated within VMC, vindicates the results obtained very recently within the diagrammatic expansion of the Gutzwiller wave function method [cf. Zegrodnik, Biborski, Fidrysiak, and Spałek, Phys. Rev. B 99, 104511 (2019)]. Subsequently, the nature of the d−wave pairing is investigated by means of recently proposed minimal-size real-space d-wave pairing operators [Moreo and Dagotto, Phys. Rev. B 100, 214502 (2019)]. An emergence of the long-range superconducting ordering for both d and p orbitals is reported by analyzing the corresponding off-diagonal pair-pair correlation functions. The dominant character of d-wave pairing on d orbitals is confirmed. Additionally, the trial wave function is used to investigate the magnetic properties of the system. The analysis of spin-spin correlation functions is carried out and shows antiferromagnetic q=(π,π), short-range order, as expected. For the sake of completeness, the charge gap has been estimated, which for the parent compound takes the value ΔCG≈1.78±0.51eV, and agrees with values reported experimentally for the cuprates.

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