Combined density functional and dynamical cluster quantum Monte Carlo calculations of the three-band Hubbard model for hole-doped cuprate superconductors

Abstract

Using a combined local density functional theory (DFT-LDA) and quantum Monte Carlo (QMC) dynamic cluster approximation approach, the parameter dependence of the superconducting transition temperature Tc of several single-layer hole-doped cuprate superconductors with experimentally very different Tc max is investigated. The parameters of two different three-band Hubbard models are obtained using the LDA and the downfolding N th-order muffin-tin orbital technique with N = 0 and 1 respectively. QMC calculations on 4-site clusters show that the d-wave transition temperature Tc depends sensitively on the parameters. While the N =1MTO basis set which reproduces all three pdσ bands leads to a d-wave transition, the N =0 set which merely reproduces the LDA Fermi surface and velocities does not.

Emery vs. Hubbard model for cuprate superconductors: a composite operator method study

“…For U > 4, the transition is always of chargetransfer type with ∆ 2.6. On the other hand, it is known that several many-body treatments fail to reproduce the insulating behavior at half filling 43 unless ∆ exceeds 3 eV . Assuming a reasonable value of t pd ≈ 1e V 43 , in our analysis we naturally obtain the charge-transfer insulator for a wider range of ∆ and U without any adjustment, thus being more consistent with the ab-initio predictions for ∆ c in cuprates that hardly exceed 3 eV 43 than other many-body treatments that seems to underestimate the insulating phase.…”

“…The results presented in this subsection have been obtained by using the first criterion, namely the jump in µ(∆). It follows from ab-initio calculations for singlelayer cuprates 43 that typical values of the ratio t pp /t pd range between 0.16 and 0.7. As shown in Fig.…”

“…Such a basis has already been assessed 64 in the case of the Emery model without direct oxygen-oxygen hopping term. In this manuscript, (i) we add this latter term to the Hamiltonian under analysis, as this term appears non-negligible in cuprates from all available ab-initio estimates (see for instance 20,43,[53][54][55][56] ), (ii) we propose an alternative choice for the fourth field, which will take into account not only the d-electron spin fluctuations, but also the charge and pair ones, and (iii) we focus our study onto the single-particle and the thermodynamic properties of the model, in order to analyze the dependence of these latter on the additional hopping term and check the validity of the Zhang and Rice scenario.…”

“…the variational Monte Carlo method 37,38 and the Constraint Path Monte Carlo technique 39,40 . Dynamical Mean Field Theory (DMFT) methods [41][42][43][44][45][46] are capable to solve the model exactly in the limit of infinite dimensions, while in the case of finite dimensions, the spatial dependence of the correlation functions appears to be oversimplified. An extension to DMFT, called Cluster Perturbation Theory 47,48 , has also been applied to the Emery model (for a review on quantum cluster theories see 49,50 and references therein).…”

The 3-band Hubbard-model versus the 1-band model for the high-T c cuprates: Pairing dynamics, superconductivity and the ground-state phase diagram

“…In this picture, next-nearest neighbor hoppings are very small compared to nearest-neighbor terms (if again oxygen-oxygen hopping t pp is taken into account). What we will show in our calculations is that the 3BH-model and a single-band t-t -U Hubbard model with a significant value for t (which may be taken as an empirical parameter adjusted to fit the Fermi-surface topology [27]) exhibit a similar low-energy (here specifically, T = 0) physics concerning the qualitative behavior of the ground-state phase diagram [28] and of the single-particle excitations including the asymmetry as a function of h-and e-doping.…”