Quasiparticle Bands in Cuprates by Quantum-Chemical Methods: Towards an<i>Ab Initio</i>Description of Strong Electron Correlations

Hozoi, Liviu; Laad, M. S.

doi:10.1103/physrevlett.99.256404

Cited by 26 publications

(39 citation statements)

References 37 publications

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“…Since it is important to accurately describe the charge distribution at sites in the immediate neighborhood, [32][33][34] we explicitly include in the actual cluster the closest six A-ion neighbors and the six adjacent IrO 6 octahedra around the reference IrO 6 unit for which the Ir d-d excitations are explicitly computed, see also Refs. 24,25,35-37.…”

Section: Ab Initio Calculation Of D-d Excitationsmentioning

confidence: 99%

Longer-range lattice anisotropy strongly competing with spin-orbit interactions in pyrochlore iridates

Hozoi¹,

Gretarsson²,

Clancy³

et al. 2014

Phys. Rev. B

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In the search for topological phases in correlated electron systems, materials with 5d transitionmetal ions, in particular, the iridium-based pyrochlores A2Ir2O7, provide fertile grounds. Several novel topological states have been predicted but the actual realization of such states is believed to critically depend on the strength of local potentials arising from distortions of the IrO6 cages. We test this hypothesis by measuring with resonant inelastic x-ray scattering the electronic level splittings in the A=Y, Eu systems, which we show to agree very well with ab initio quantum chemistry electronic-structure calculations for the series of materials with A=Sm, Eu, Lu, and Y. We find, however, that not distortions of the IrO6 octahedra are the primary source for quenching the spin-orbit interaction, but longer-range lattice anisotropies which inevitably break the local cubic symmetry.

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Section: Ab Initio Calculation Of D-d Excitationsmentioning

confidence: 99%

Longer-range lattice anisotropy strongly competing with spin-orbit interactions in pyrochlore iridates

Hozoi¹,

Gretarsson²,

Clancy³

et al. 2014

Phys. Rev. B

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“…In the (effective) one-electron tight-binding models, the variation of the inphase and out-of-phase overlap of the atomic orbitals that form the Bloch orbitals causes a dispersion of the orbital energies, while in explicit n-electron treatments of the band structure, band dispersion arises from the variations of the hopping amplitudes along the different crystal directions. [112][113][114][115] Here, the broadening of the valence and conduction bands is caused by the inhomogeneity of the structure due to the movement of the nuclei, which introduces variations in the relative energies of the relevant n-electron states. Furthermore, the DRF method showed as an adequate approach to treat the polarization in crystalline environments under the condition that the largest polarization effects are treated in the wave function, and that the artificial polarization of the ground state is removed from the system.…”

Section: Optical Absorptionmentioning

confidence: 99%

Ab initioabsorption spectrum of NiO combining molecular dynamics with the embedded cluster approach in a discrete reaction field

et al. 2012

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We developed a procedure that combines three complementary computational methodologies to improve the theoretical description of the electronic structure of nickel oxide. The starting point is a Car-Parrinello molecular dynamics simulation to incorporate vibrorotational degrees of freedom into the material model. By means of complete active space self-consistent field second-order perturbation theory (CASPT2) calculations on embedded clusters extracted from the resulting trajectory, we describe localized spectroscopic phenomena on NiO with an efficient treatment of electron correlation. The inclusion of thermal motion into the theoretical description allows us to study electronic transitions that, otherwise, would be dipole forbidden in the ideal structure and results in a natural reproduction of the band broadening. Moreover, we improved the embedded cluster model by incorporating self-consistently at the complete active space self-consistent field (CASSCF) level a discrete (or direct) reaction field (DRF) in the cluster surroundings. The DRF approach offers an efficient treatment of electric response effects of the crystalline embedding to the electronic transitions localized in the cluster. We offer accurate theoretical estimates of the absorption spectrum and the density of states around the Fermi level of NiO, and a comprehensive explanation of the source of the broadening and the relaxation of the charge transfer states due to the adaptation of the environment.

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“…On the other, however, figuring out the detailed features behind the material dependency can provide the crucial hint for further understanding of superconductivity and other related properties. In fact, many directly or indirectly related theoretical studies have been performed on this issue13141516171819202122232425…”

mentioning

confidence: 99%

Quasiparticle self-consistent GW study of cuprates: electronic structure, model parameters and the two-band theory for Tc

Jang

Kotani

Kino

et al. 2015

Sci Rep

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Despite decades of progress, an understanding of unconventional superconductivity still remains elusive. An important open question is about the material dependence of the superconducting properties. Using the quasiparticle self-consistent GW method, we re-examine the electronic structure of copper oxide high-Tc materials. We show that QSGW captures several important features, distinctive from the conventional LDA results. The energy level splitting between and is significantly enlarged and the van Hove singularity point is lowered. The calculated results compare better than LDA with recent experimental results from resonant inelastic xray scattering and angle resolved photoemission experiments. This agreement with the experiments supports the previously suggested two-band theory for the material dependence of the superconducting transition temperature, Tc.

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Quasiparticle Bands in Cuprates by Quantum-Chemical Methods: Towards anAb InitioDescription of Strong Electron Correlations

Cited by 26 publications

References 37 publications

Longer-range lattice anisotropy strongly competing with spin-orbit interactions in pyrochlore iridates

Longer-range lattice anisotropy strongly competing with spin-orbit interactions in pyrochlore iridates

Ab initioabsorption spectrum of NiO combining molecular dynamics with the embedded cluster approach in a discrete reaction field

Quasiparticle self-consistent GW study of cuprates: electronic structure, model parameters and the two-band theory for Tc

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