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Related papers: Dynamical Vertex Approximation

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We give an elementary introduction to a recent diagrammatic extension of dynamical mean field theory (DMFT) coined dynamical vertex approximation (D$\Gamma$A). This approach contains the important local correlations of DMFT, giving, among…

Strongly Correlated Electrons · Physics 2009-03-18 K. Held , A. A. Katanin , A. Toschi

With an increasing complexity of nanoscopic systems and the modeling thereof, new theoretical tools are needed for a reliable calculation of complex systems with strong electronic correlations. To this end, we propose a new approach based…

Strongly Correlated Electrons · Physics 2010-06-22 Angelo Valli , Giorgio Sangiovanni , Olle Gunnarsson , Alessandro Toschi , Karsten Held

Recently, diagrammatic extensions of dynamical mean field theory (DMFT) have been proposed for including short- and long-range correlations beyond DMFT on an equal footing. We employ one of these, the dynamical vertex approximation…

Strongly Correlated Electrons · Physics 2016-03-23 T. Schaefer , A. Toschi , K. Held

We have implemented the dynamical vertex approximation (D$\Gamma$A) in its full parquet-based version to include spatial correlations on all length scales and in {\sl all} scattering channels. The algorithm is applied to study the…

Strongly Correlated Electrons · Physics 2015-06-23 A. Valli , T. Schäfer , P. Thunström , G. Rohringer , S. Andergassen , G. Sangiovanni , K. Held , A. Toschi

In this work, we adapt the formalism of the dynamical vertex approximation (D$\Gamma$A), a diagrammatic approach including many-body correlations beyond the dynamical mean-field theory, to the case of attractive onsite interactions. We…

Strongly Correlated Electrons · Physics 2021-07-13 Lorenzo Del Re , Massimo Capone , Alessandro Toschi

In this paper, we investigate how nonlocal correlations affect, selectively, the physics of correlated electrons over different energy scales, from the Fermi level to the band-edges. This goal is achieved by applying a diagrammatic…

Strongly Correlated Electrons · Physics 2016-10-24 G. Rohringer , A. Toschi

We generalize the formalism of the dynamical vertex approximation (D$\Gamma$A) -- a diagrammatic extension of the dynamical mean-field theory (DMFT)-- to treat magnetically ordered phases. To this aim, we start by concisely illustrating the…

Strongly Correlated Electrons · Physics 2021-08-18 Lorenzo Del Re , Alessandro Toschi

We present a novel approximation scheme for the treatment of strongly correlated electrons in arbitrary crystal lattices. The approach extends the well-known dynamical mean field theory to include nonlocal two-site correlations of arbitrary…

Strongly Correlated Electrons · Physics 2012-04-16 Torben Jabben , Norbert Grewe , Sebastian Schmitt

The Dynamical Cluster Approximation (DCA) is used to study non-local corrections to the dynamical mean field phase diagram of the two-dimensional Hubbard model. Regions of antiferromagnetic, d-wave superconducting, pseudo-gapped non-Fermi…

Strongly Correlated Electrons · Physics 2009-10-31 M. Jarrell , Th. Maier , M. H. Hettler , A. N. Tahvildarzadeh

The dynamical mean-field concept of approximating an unsolvable many-body problem in terms of the solution of an auxiliary quantum impurity problem, introduced to study bulk materials with a continuous energy spectrum, is here extended to…

Strongly Correlated Electrons · Physics 2011-03-04 Nan Lin , C. A. Marianetti , Andrew J. Millis , David R. Reichman

We compute the spin susceptibility of the two-dimensional Hubbard model away from half-filling, and analyze the impact of frequency dependent vertex corrections as obtained from the dynamical mean field theory (DMFT). We find that the local…

Strongly Correlated Electrons · Physics 2018-06-13 Demetrio Vilardi , Ciro Taranto , Walter Metzner

By means of the dynamical vertex approximation (D$\Gamma$A) we include spatial correlations on all length scales beyond the dynamical mean field theory (DMFT) for the half-filled Hubbard model in three dimensions. The most relevant changes…

Strongly Correlated Electrons · Physics 2012-08-28 G. Rohringer , A. Toschi , A. A. Katanin , K. Held

Dynamical mean-field theory (DMFT) is a non-perturbative technique for the investigation of correlated electron systems. Its combination with the local density approximation (LDA) has recently led to a material-specific computational scheme…

Strongly Correlated Electrons · Physics 2009-11-10 D. Vollhardt , K. Held , G. Keller , R. Bulla , Th. Pruschke , I. A. Nekrasov , V. I. Anisimov

The dynamical mean-field theory (DMFT) is a widely applicable approximation scheme for the investigation of correlated quantum many-particle systems on a lattice, e.g., electrons in solids and cold atoms in optical lattices. In particular,…

Strongly Correlated Electrons · Physics 2015-05-30 D. Vollhardt , K. Byczuk , M. Kollar

The dual-fermion approach provides a formally exact prescription for calculating properties of a correlated electron system in terms of a diagrammatic expansion around dynamical mean-field theory (DMFT). Most practical implementations,…

Strongly Correlated Electrons · Physics 2017-08-02 Jan Gukelberger , Evgeny Kozik , Hartmut Hafermann

We discuss analytical approximation schemes for the dynamics of diluted spin models. The original dynamics of the complete set of degrees of freedom is replaced by a hierarchy of equations including an increasing number of global…

Statistical Mechanics · Physics 2009-11-10 Guilhem Semerjian , Martin Weigt

The optical conductivity contains relevant information on the properties of correlated electron systems. In infinite dimensions, where dynamical mean field theory becomes exact, vertex corrections can be neglected and the conductivity…

Strongly Correlated Electrons · Physics 2021-03-17 Olivier Simard , Shintaro Takayoshi , Philipp Werner

Strong electronic correlations pose one of the biggest challenges to solid state theory. We review recently developed methods that address this problem by starting with the local, eminently important correlations of dynamical mean field…

Strongly Correlated Electrons · Physics 2018-05-23 G. Rohringer , H. Hafermann , A. Toschi , A. A. Katanin , A. E. Antipov , M. I. Katsnelson , A. I. Lichtenstein , A. N. Rubtsov , K. Held

We introduce a numerical algorithm to stochastically sample the dual fermion perturbation series around the dynamical mean field theory, generating all topologies of two-particle interaction vertices. We show results in the weak and strong…

Strongly Correlated Electrons · Physics 2016-07-07 Sergei Iskakov , Andrey E. Antipov , Emanuel Gull

The dual boson approach [Ann. Phys. 327, 1320 (2012)] provides a means to construct a diagrammatic expansion around the extended dynamical mean-field theory (EDMFT). In this paper, we present the numerical implementation of the approach and…

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