Electronic structure of strongly correlated materials

Анисимов, В. И.; Avella, Adolfo; Mancini, Ferdinando

doi:10.1063/1.3518902

Cited by 55 publications

(79 citation statements)

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“…We consider here the transition metal system for simplicity and adopt the first-principles LDA+U Hamiltonian, which is based on the tight-binding linear muffin-tin orbital method [13,14].…”

Section: Lda+u Hamiltonian and Mla Wavefunctionmentioning

confidence: 99%

First-principles Theory of the Momentum-dependent Local Ansatz for Correlated Electron System

Chandra

Kakehashi

2015

Physics Procedia

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The momentum-dependent local-ansatz (MLA) wavefunction describes well correlated electrons in solids in both the weak and strong interaction regimes. In order to apply the theory to the realistic system, we have extended the MLA to the first-principles version using the tight-binding LDA+U Hamiltonian. We demonstrate for the paramagnetic Fe that the first-principles MLA can describe a reasonable correlation energy gain and suppression of charge fluctuations due to electron correlations. Furthermore, we show that the MLA yields a distinct momentum dependence of the momentum distribution, and thus improves the Gutzwiller wavefunction.

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“…We consider here the transition metal system for simplicity and adopt the first-principles LDA+U Hamiltonian, which is based on the tight-binding linear muffin-tin orbital method [13,14].…”

Section: Lda+u Hamiltonian and Mla Wavefunctionmentioning

confidence: 99%

First-principles Theory of the Momentum-dependent Local Ansatz for Correlated Electron System

Chandra

Kakehashi

2015

Physics Procedia

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“…Therefore it is worthwhile to extend the MLA to the realistic system towards first-principles calculations. Let us consider the first-principles LDA+U Hamiltonian which is based on the tight-binding linear muffin-tin orbital 65,26 .…”

Section: Towards the First-principles Mlamentioning

confidence: 99%

“…In the exact diagonalization method (ED), one directly solves the eigen-value problem for a small cluster with use of the Lanczos method 20 . In the quantum Monte-Carlo method (QMC), we reduce the quantum mechanical average into a classical one with use of the Suzuki-Trotter theorem, and apply the Monte-Carlo technique 21,22 . In the past two decades, effective medium approaches such as the dynamical coherent potential approximation (CPA) 23,24 and the dynamical mean field theory (DMFT) 25,26 have been developed. There we replace the surrounding interactions with a momentum-independent effective medium in the Green function and determine the medium self-consistently solving an impurity problem with use of many-body techniques.…”

Section: Introductionmentioning

confidence: 99%

Momentum-dependent local ansatz approach to correlated electrons

et al. 2014

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The wavefunction method provides us with a useful tool to describe electron correlations in solids at the ground state. In this paper we review the recent development of the momentum-dependent local ansatz wavefunction (MLA). It is constructed by taking into account two-particle excited states projected onto the local orbitals, and the momentum-dependent amplitudes of these states are chosen as variational parameters. The MLA describes accurately correlated electron states from the weak to the intermediate Coulomb interaction regime in infinite dimensions, and works well even in the strongly correlated region by introducing a new starting wavefunction called the hybrid (HB) wavefunction. The MLA-HB is therefore shown to overcome the limitation of the original local ansatz (LA) wavefunction as well as the Gutzwiller wavefunction. In particular, the calculated quasiparticle weight vs Coulomb interaction curve is shown to be close to that obtained by the numerical renormalization group approach. It is also shown that the MLA is applicable to the first-principles Hamiltonian.Comment: 32 pages, 7 figure

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“…Alternative approach to quantitative description of correlated electrons is the first-2/18 principles DMFT (DCPA) combined with the LDA+U Hamiltonian. [20][21][22][23][24][25] The LDA+DMFT is a powerful method to strongly correlated electrons and has been applied to many systems.…”

Section: Introductionmentioning

confidence: 99%

First-Principles Momentum Dependent Local Ansatz Approach to the Ground-State Properties of Iron-Group Transition Metals

Kakehashi

Chandra

2016

J. Phys. Soc. Jpn.

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The ground-state properties of iron-group transition metals from Sc to Cu have been investigated on the basis of the first-principles momentum dependent local ansatz (MLA) theory. Correlation energy gain is found to show large values for Mn and Fe: 0.090 Ry (Mn) and 0.094 Ry (Fe). The Hund-rule coupling energies are found to be 3000 K (Fe), 1400 K (Co), and 300 K (Ni). It is sugested that these values can resolve the inconsistency in magnetic energy between the density functional theory and the first-principles dynamical coherent potential approximation theory at finite temperatures. Charge fluctuations are shown to be suppressed by the intra-orbital correlations and inter-orbital charge-charge correlations, so that they show nearly constant values from V to Fe: 1.57 (V and Cr), 1.52 (Mn), and 1.44 (Fe), which are roughly twice as large as those obtained by the d band model. The amplitudes of local moments are enhanced by the intra-orbital and inter-orbital spin-spin correlations and show large values for Mn and Fe: 2.87 (Mn) and 2.58 (Fe). These values are in good agreement with the experimental values estimated from the effective Bohr magneton number and the inner core photoemission data. KEYWORDS: first-principles variational theory, momentum-dependent local ansatz, iron-group transition metals, electron correlations, correlation energy, charge fluctuations, amplitude of local moment * yok@sci.u-ryukyu.ac.jp, to be published in J. Phys. Soc. Jpn. 85 (2016).

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Electronic structure of strongly correlated materials

Cited by 55 publications

References 0 publications

First-principles Theory of the Momentum-dependent Local Ansatz for Correlated Electron System

First-principles Theory of the Momentum-dependent Local Ansatz for Correlated Electron System

Momentum-dependent local ansatz approach to correlated electrons

First-Principles Momentum Dependent Local Ansatz Approach to the Ground-State Properties of Iron-Group Transition Metals

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