Dynamical mean‐field theory for correlated electrons

Vollhardt, D.

doi:10.1002/andp.201100250

Cited by 83 publications

(84 citation statements)

References 154 publications

(188 reference statements)

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“…3 and 4 and references therein) have shown that more elaborate methods such as dynamical mean field theory [5][6][7] or GW-based approaches 8 are needed to successfully model interfaces of strongly correlated electronic systems and predict the direction of charge transfer. While many-body techniques in combination with DFT methods are sufficient for this task, they remain computationally demanding, particularly when it is necessary to account for the important structural relaxations and phase transitions occurring at interfaces.…”

Section: 2mentioning

confidence: 99%

Structural phase transitions of the metal oxide perovskites SrTiO3, LaAlO3, and LaTiO3studied with a scree

et al. 2013

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We have investigated the structural phase transitions of the transition metal oxide perovskites SrTiO 3 , LaAlO 3 , and LaTiO 3 using the screened hybrid density functional of Heyd, Scuseria, and Ernzerhof (HSE06). We show that HSE06-computed lattice parameters, octahedral tilts, and rotations, as well as electronic properties, are significantly improved over semilocal functionals. We predict the crystal-field splitting ( CF ) resulting from the structural phase transition in SrTiO 3 and LaAlO 3 to be 3 meV and 10 meV, respectively, in excellent agreement with experimental results. HSE06 identifies correctly LaTiO 3 in the magnetic states as a Mott insulator. Also, it predicts that the GdFeO 3 -type distortion in nonmagnetic LaTiO 3 will induce a large CF of 410 meV. This large crystal-field splitting associated with the large magnetic moment found in the G-type antiferromagnetic state suggests that LaTiO 3 has an induced orbital order, which is confirmed by the visualization of the highest occupied orbitals. These results strongly indicate that HSE06 is capable of efficiently and accurately modeling perovskite oxides and promises to efficiently capture the physics at their heterointerfaces.

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Section: 2mentioning

confidence: 99%

Structural phase transitions of the metal oxide perovskites SrTiO3, LaAlO3, and LaTiO3studied with a scree

et al. 2013

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“…The evolution of the spectra with increasing U shows the well known transfer of spectral weight from the coherent quasiparticle peak centered on ω = 0 to Hubbard bands at ±U/2 (in IPES one only observes the part for ω > 0) [25][26][27][28]. For U 1.2 DMFT finds a metallic and for U 1.5 a Mott insulating ground state.…”

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confidence: 80%

“…The local method developed into a full ab-initio approach as a post Hartree-Fock or post density functional theory calculation similar to coupled cluster or configuration interaction schemes [21][22][23][24]. Here we exemplify how dynamical mean-field theory (DMFT) [25][26][27][28] can merge these two theoretical approaches for core level spectroscopy.…”

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confidence: 99%

Bands, resonances, edge singularities and excitons in core level spectroscopy investigated within the dynamical mean-field theory

Haverkort¹,

Sangiovanni²,

Hansmann³

et al. 2014

EPL

105

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PACS 78.70.Dm -X-ray absorption spectra PACS 79.60.-i -Photoemission and photoelectron spectra PACS 78.20.Bh -Theory, models, and numerical simulation Abstract -Using a recently developed impurity solver we exemplify how dynamical mean field theory captures band excitations, resonances, edge singularities and excitons in core level x-ray absorption (XAS) and core level photo electron spectroscopy (cPES) on metals, correlated metals and Mott insulators. Comparing XAS at different values of the core-valence interaction shows how the quasiparticle peak in the absence of core-valence interactions evolves into a resonance of similar shape, but different origin. Whereas XAS is rather insensitive to the metal insulator transition, cPES can be used, due to nonlocal screening, to measure the amount of local charge fluctuation.Core level photoemission (cPES) and core level x-ray absorption spectroscopy (XAS) have long been valuable tools in the field of material research for a huge range of compounds with a different degree of correlations [1]. For example, XAS can probe the unoccupied density of states in GaAs, Al or Hydrocarbons [2], local properties of correlated d-shells in transition-metal compounds like the cuprates [3][4][5], or the atomic like ground state symmetry of rare earth ions in heavy Fermion compounds and impurities in an aluminum garnet used as laser medium [6][7][8][9]. Interestingly, the same experiment seems to measure a different observable (empty density of states or local symmetry of the occupied wave-function) depending on the amount of correlations in the material. This dichotomy is also present in theory. The theoretical efforts for the description of cPES and XAS can roughly be divided into two approaches based on an itinerant or local starting point.In the itinerant approach one approximates the interactions between electrons by a (mean-field) potential. As a result one obtains a set of freely moving particles. This is the case for Hartee-Fock or density functional theory (in the local density approximation) calculations. On this level of theory XAS is identified as the unoccupied single particle density of states and cPES as a delta-function representing the occupied core density of states [10]. The core-valence interaction can be modeled as an additional potential that suddenly arrises after the photon absorption, leading to an edge singularity in the spectral function [11][12][13][14]. For many systems, including most of the transition-metal and rare earth oxides, it has been realized early on that the inclusion of the explicit core-valence interactions beyond a mean-field potential is crucial. Many of these core level edges are much more determined by the local multiplet structure than by the band-structure of the material. Sawatzky and coworkers used local models approximating a solid by a single atom in an effective potential (crystal field) or by a small cluster (ligand field theory) [1,7]. These cluster models can be extended to include the band width of the material at the level of an...

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“…In addition, more review articles will be solicited. The Einstein Lecture series, i. e. invited articles from internationally leading scientists, is continued -as evidenced by the fine contribution from Dieter Vollhardt [4] about dynamical meanfield theory for correlated electrons in this issue.…”

mentioning

confidence: 94%

Editorial: Wecome to the new Annalen der Physik

Fuchs¹

2011

Annalen der Physik

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Dynamical mean‐field theory for correlated electrons

Cited by 83 publications

References 154 publications

Structural phase transitions of the metal oxide perovskites SrTiO3, LaAlO3, and LaTiO3studied with a scree

Structural phase transitions of the metal oxide perovskites SrTiO3, LaAlO3, and LaTiO3studied with a scree

Bands, resonances, edge singularities and excitons in core level spectroscopy investigated within the dynamical mean-field theory

Editorial: Wecome to the new Annalen der Physik

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