Realistic many-body approaches to materials with strong nonlocal correlations

Lechermann, Frank; Lichtenstein, A. I.; Potthoff, Michael

doi:10.1140/epjst/e2017-70051-3

Cited by 10 publications

(6 citation statements)

References 117 publications

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“…Symmetry constraints on the structure of the k-dependent correlations may enable improved accuracy. Recent extensions of DMFT aim to incorporate nonlocal correlations [179].…”

Section: Discussionmentioning

confidence: 99%

Model Hamiltonian for strongly correlated systems: Systematic, self-consistent, and unique construction

Requist

Gross

2019

Phys. Rev. B

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An interacting lattice model describing the subspace spanned by a set of strongly correlated bands is rigorously coupled to density functional theory to enable ab initio calculations of geometric and topological material properties. The strongly correlated subspace is identified from the occupation number band structure as opposed to a mean-field energy band structure. The self-consistent solution of the many-body model Hamiltonian and a generalized Kohn-Sham equation exactly incorporates momentum-dependent and crystal-symmetric correlations into electronic structure calculations in a way that does not rely on a separation of energy scales. Calculations for a multiorbital Hubbard model demonstrate that the theory accurately reproduces the many-body macroscopic polarization. I.arXiv:1809.07719v2 [cond-mat.str-el]

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“…Symmetry constraints on the structure of the k-dependent correlations may enable improved accuracy. Recent extensions of DMFT aim to incorporate nonlocal correlations [179].…”

Section: Discussionmentioning

confidence: 99%

Model Hamiltonian for strongly correlated systems: Systematic, self-consistent, and unique construction

Requist

Gross

2019

Phys. Rev. B

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“…Efforts to combine density functional theory with these post-DMFT methods are the subject of current active research. Readers interested in these efforts will find them discussed in references [159,[259][260][261][262][263][264][265][266][267][268].…”

Section: Applicationsmentioning

confidence: 99%

Beyond Quantum Cluster Theories: Multiscale Approaches for Strongly Correlated Systems

Fotso¹,

Tam²,

Moreno³

2020

Preprint

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The degrees of freedom that confer to strongly correlated systems their many intriguing properties also render them fairly intractable through typical perturbative treatments. For this reason, the mechanisms responsible for these technologically promising properties remain mostly elusive. Computational approaches have played a major role in efforts to fill this void. In particular, dynamical mean field theory (DMFT) and its cluster extension, the dynamical cluster approximation (DCA) have allowed significant progress. However, despite all the insightful results of these embedding schemes, computational constraints, such as the minus sign problem in Quantum Monte Carlo (QMC), and the exponential growth of the Hilbert space in exact diagonalization (ED) methods, still limit the length scale within which correlations can be treated exactly in the formalism. A recent advance to overcome these difficulties is the development of multiscale many body approaches whereby this challenge is addressed by introducing an intermediate length scale between the short length scale where correlations are treated exactly using a cluster solver such QMC or ED, and the long length scale where correlations are treated in a mean field manner. At this intermediate length scale correlations can be treated perturbatively. This is the essence of multiscale many-body methods. We will review various implementations of these multiscale many-body approaches, the results they have produced, and the outstanding challenges that should be addressed for further advances.

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“…Experimentally, the angle resolved photoemission spectroscopy (ARPES) was used to probe the presence of Hubbard bands [13]. Here, in this communication we review the theoretical background of the solution of DMFT equation implementing CT-QMC technique with hybridization expansion to explain the phenomena of Mott-Hubbard kinetics in superstructure of strongly correlated systems La x Sr 1−x VO 3 [14,15,16,17,18,19]. The process of implementation of reconstructing data from CT-QMC through maximum entropy model, which is useful to predict Mott phase transition of TMOs, has been discussed [20,21,22,23,24,25,26,27].…”

Section: Introductionmentioning

confidence: 99%

A Continuous Time Quantum Monte Carlo as an Impurity Solver for Strongly Correlated System

et al. 2021

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We assess the continuous-time quantum Monte Carlo (CT-QMC) technique with hybridization expansion for solvingthe electronic structure of the strongly correlated system LaxSr1−xVO3 . The impurity solver method implemented here shows the fair agreement with the other available Monte Carlo techniques. From the study, it is found that the CT-QMC technique clearly distinguishes metallic phase, quasiparticle phase and insulating phases of the system depending upon the strength of the correlation. In case of La0.33Sr0.67VO3 system the metal-insulator transition is found to be at U = 4.5 eV for β = 6(eV)−1. The value of U depends with the value of β, and also the value of Hund’s coupling (J) and bandwidth (W). This technique allows the particle to exchange with the reservoir of the particles and the impurity sites, which is accounted numerically to treat the temporal fluctuation of the fermionic systems termed as dynamical mean field theory (DMFT). This theory is used to explain the phenomena of MottHubbard metal insulator transition of the materials which are applicable for designing the Mottronics, Neuromorphic computing, Quantum computing and resistive memory devices.

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Realistic many-body approaches to materials with strong nonlocal correlations

Cited by 10 publications

References 117 publications

Model Hamiltonian for strongly correlated systems: Systematic, self-consistent, and unique construction

Model Hamiltonian for strongly correlated systems: Systematic, self-consistent, and unique construction

Beyond Quantum Cluster Theories: Multiscale Approaches for Strongly Correlated Systems

A Continuous Time Quantum Monte Carlo as an Impurity Solver for Strongly Correlated System

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