Conserving approximations for strongly fluctuating electron systems. II. Numerical results and parquet extension

Bickers, N. E.; White, Steven R.

doi:10.1103/physrevb.43.8044

Cited by 311 publications

(319 citation statements)

References 32 publications

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“…While the combination of the particle-particle and particlehole ladders does not help much, the inclusion of diagrams with crossed rungs in X ladders does improve the result. This finding is consistent with the intuition of Bickers and White [47], who suggested that ladders with crossed rungs should strongly renormalize the particle-particle and particlehole ladder contributions, and argued that one should therefore work with a renormalized U . (It should be kept in mind that the X-ladder class of diagrams cannot be summed analytically via a Dyson equation.)…”

Section: Relevant Diagramssupporting

confidence: 90%

On the dangers of partial diagrammatic summations: Benchmarks for the two-dimensional Hubbard model in the weak-coupling regime

Gukelberger

Werner

2015

Phys. Rev. B

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We study the two-dimensional Hubbard model in the weak-coupling regime and compare the self-energy obtained from various approximate diagrammatic schemes to the result of diagrammatic Monte Carlo simulations, which sum up all weak-coupling diagrams up to a given order. While dynamical mean-field theory provides a good approximation for the local part of the self-energy, including its frequency dependence, the partial summation of bubble and/or ladder diagrams typically yields worse results than second-order perturbation theory. Even widely used self-consistent schemes such as GW or the fluctuation-exchange approximation (FLEX) are found to be unreliable. Combining the dynamical mean-field self-energy with the nonlocal component of GW in GW + DMFT yields improved results for the local self-energy and nonlocal self-energies of the correct order of magnitude, but here, too, a more reliable scheme is obtained by restricting the nonlocal contribution to the second-order diagram. FLEX + DMFT is found to give accurate results in the low-density regime, but even worse results than FLEX near half-filling.

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Section: Relevant Diagramssupporting

confidence: 90%

On the dangers of partial diagrammatic summations: Benchmarks for the two-dimensional Hubbard model in the weak-coupling regime

Gukelberger

Werner

2015

Phys. Rev. B

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“…22,34 In this case, in order to avoid double counting, as in Ref. 3, the scattering amplitude should start from the third order in the screened interaction. 21,34 Such an additional term can be regarded as vertex corrections to the G 0 W 0 self-energy.…”

Section: G 0 W 0 and T Approximationmentioning

confidence: 99%

“…[2][3][4][5] The second term, ⌫ e-ph , represents the contribution from inelastic electron-phonon ͑e-ph͒ scattering. This contribution is usually considered as comparable with the electron-electron part only close to the Fermi level, within a typical phonon energy ប D ͑ D is the Debye cutoff energy͒.…”

Section: Introductionmentioning

confidence: 99%

“…For example, similar to the electron-phonon interaction, the electron-electron one can be considered as realized through the exchanging by a number of varieties of "bosons" ͑the aforementioned fluctuations͒ composed of electrons and holes, which themselves strongly interact through the exchange by other bosons. 3 Depending on how many varieties of these bosons are involved in the description of the e-e interaction within an approach, one obtains different results for contribution of the exchangecorrelation effects to quasiparticle properties.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical study of quasiparticle inelastic lifetimes as applied to aluminum

et al. 2008

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We present a comparative analysis of different microscopic approaches to quasiparticle properties in metals. Aluminum is chosen as an application object, since it exhibits characteristics many of which are well-described in the jellium model. Within this model, we consider how different levels of physical elaboration of the electron-electron interaction affect the imaginary part of the quasiparticle self-energy and the quasiparticle renormalization constant. Also, we present ab initio calculations of the quasiparticle lifetime in crystalline aluminum with the use of both the linear muffin-tin orbital method and the plane-wave pseudopotential theory. To complete the picture of inelastic scattering effects in aluminum, we report first-principles calculations on electron-phonon interaction and on the phonon mediated contribution to the lifetime. The total inelastic lifetime broadening is compared with experimental data known from the literature.

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“…8 Attempts to go beyond one-particle renormalizations by introducing explicit vertex corrections and a two-particle selfconsistency either do not lead to analytically solvable equations or have not yet produced the desired Kondo asymptotics in SIAM. 9,10 The aim of this paper is to construct an analytically controllable approximation that would reliably interpolate between the weak-and strong-coupling regimes in models with a screened electron repulsion. To this purpose we use an appropriately renormalized diagrammatic many-body expansion.…”

Section: Introductionmentioning

confidence: 99%

Analytic impurity solver with Kondo strong-coupling asymptotics

Janiš

Augustinský

2007

Phys. Rev. B

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We present an analytic universal impurity solver for strongly correlated electrons. We extend the many-body perturbation expansion via suitable two-particle renormalizations from the Fermi-liquid regime to the critical region of the metal-insulator transition. The reliability of the approximation in the strong-coupling limit is demonstrated by reproducing the Kondo scale in the single-impurity Anderson model. We disclose the origin of the Kondo resonance in terms of Feynman diagrams and find criteria for the existence of the proper Kondo asymptotic behavior in approximate theories.

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Conserving approximations for strongly fluctuating electron systems. II. Numerical results and parquet extension

Cited by 311 publications

References 32 publications

On the dangers of partial diagrammatic summations: Benchmarks for the two-dimensional Hubbard model in the weak-coupling regime

On the dangers of partial diagrammatic summations: Benchmarks for the two-dimensional Hubbard model in the weak-coupling regime

Theoretical study of quasiparticle inelastic lifetimes as applied to aluminum

Analytic impurity solver with Kondo strong-coupling asymptotics

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