For the calculation of charge excitations as those observed in, e.g., photoemission spectroscopy or in electron-energy-loss spectroscopy, a correct description of ground-state charge properties is essential. In strongly correlated systems like the undoped cuprates this is a highly nontrivial problem. In this paper we derive a nonperturbative analytical approximation for the ground state of the three-band Hubbard model on an infinite, half-filled ${\mathrm{CuO}}_{2}$ plane. By comparison with projector quantum Monte Carlo calculations it is shown that the resulting expressions correctly describe the charge properties of the ground state. Relations to other approaches are discussed. The analytical ground state preserves size consistency and can be generalized for other geometries, while still being both easy to interpret and to evaluate.For the calculation of charge excitations as those observed in, e.g., photoemission spectroscopy or in electron-energy-loss spectroscopy, a correct description of ground-state charge properties is essential. In strongly correlated systems like the undoped cuprates this is a highly nontrivial problem. In this paper we derive a nonperturbative analytical approximation for the ground state of the three-band Hubbard model on an infinite, half-filled ${\mathrm{CuO}}_{2}$ plane. By comparison with projector quantum Monte Carlo calculations it is shown that the resulting expressions correctly describe the charge properties of the ground state. Relations to other approaches are discussed. The analytical ground state preserves size consistency and can be generalized for other geometries, while still being both easy to interpret and to evaluate.

arXiv:cond-mat/9904244Physical review. B, Condensed matterJul 15, 19993 citations

Metal-insulator transition in the ground state of the three-band Hubbard model at half filling

Ettore Vitali, Hao Shi, Adam Chiciak +1 more

The three-band Hubbard model is a fundamental model for understanding properties of the copper-oxygen planes in cuprate superconductors. We use cutting-edge auxiliary-field quantum Monte Carlo (AFQMC) methods to investigate ground state properties of the model in the parent compound. Large supercells combined with twist averaged boundary conditions are employed to reliably reach the thermodynamic limit. Benchmark quality results are obtained on the magnetic correlations and charge gap. A key parameter of this model is the charge-transfer energy $\mathrm{\ensuremath{\Delta}}$ between the oxygen $p$ and the copper $d$ orbitals, which appears to vary significantly across different families of cuprates and whose ab initio determination is subtle. We show that the system undergoes a quantum phase transition from an antiferromagnetic insulator to a paramagnetic metal as $\mathrm{\ensuremath{\Delta}}$ is lowered to $3\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$ .The three-band Hubbard model is a fundamental model for understanding properties of the copper-oxygen planes in cuprate superconductors. We use cutting-edge auxiliary-field quantum Monte Carlo (AFQMC) methods to investigate ground state properties of the model in the parent compound. Large supercells combined with twist averaged boundary conditions are employed to reliably reach the thermodynamic limit. Benchmark quality results are obtained on the magnetic correlations and charge gap. A key parameter of this model is the charge-transfer energy $\mathrm{\ensuremath{\Delta}}$ between the oxygen $p$ and the copper $d$ orbitals, which appears to vary significantly across different families of cuprates and whose ab initio determination is subtle. We show that the system undergoes a quantum phase transition from an antiferromagnetic insulator to a paramagnetic metal as $\mathrm{\ensuremath{\Delta}}$ is lowered to $3\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$.

arXiv:1807.06139Physical review. B./Physical review. BApr 12, 201924 citations

Ground State Properties of the Holstein–Hubbard Model

Tadahiro Miyao

arXiv:1610.09039Annales Henri PoincaréMay 31, 201813 citations

{\mathrm{CuO}}_{2}

plane. By comparison with projector quantum Monte Carlo calculations it is shown that the resulting expressions correctly describe the charge properties of the ground state. Relations to other approaches are discussed. The analytical ground state preserves size consistency and can be generalized for other geometries, while still being both easy to interpret and to evaluate.

p

and the copper

d

orbitals, which appears to vary significantly across different families of cuprates and whose ab initio determination is subtle. We show that the system undergoes a quantum phase transition from an antiferromagnetic insulator to a paramagnetic metal as $\mathrm{\ensuremath{\Delta}}$ is lowered to

3\phantom{\rule{0.28em}{0ex}}\mathrm{eV}