Tiling with triangles: parquet and $GW\gamma$ methods unified.
TLDR
In this article, the parquet formalism and Hedin's $GW\gamma approach are unified into a single theory of vertex corrections, corresponding to an exact reformulation of the Parquet equations in terms of boson exchange.Abstract:
The parquet formalism and Hedin's $GW\gamma$ approach are unified into a single theory of vertex corrections, corresponding to an exact reformulation of the parquet equations in terms of boson exchange. The method has no drawbacks compared to previous parquet solvers but has the significant advantage that the vertex functions decay quickly with frequencies and with respect to distances in real space. These properties coincide with the respective separation of the length and energy scales of the two-particle correlations into long/short-ranged and high/low-energetic.read more
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Dual fermion approach to nonlocal correlations in the Hubbard model
TL;DR: In this paper, a new diagrammatic technique is developed to describe pseudogap formation in the Hubbard-like models, which utilizes an exact transition to the dual set of variables, and therefore becomes possible to treat the irreducible vertices of an effective single-impurity problem as small parameters.
Journal ArticleDOI
Tracking the Footprints of Spin Fluctuations: A MultiMethod, MultiMessenger Study of the Two-Dimensional Hubbard Model
Thomas Schäfer,Nils Wentzell,Fedor Simkovic,Yuan-Yao He,Cornelia Hille,Marcel Klett,Christian Eckhardt,Behnam Arzhang,Viktor Harkov,François-Marie Le Régent,Alfred Kirsch,Yan Wang,Aaram J. Kim,Evgeny Kozik,E. A. Stepanov,Anna Kauch,Sabine Andergassen,Philipp Hansmann,Daniel Rohe,Y. M. Vilk,James P.F. LeBlanc,Shiwei Zhang,Andre-Marie Tremblay,Michel Ferrero,Olivier Parcollet,Antoine Georges +25 more
TL;DR: In this paper, a comparative study of state-of-the-art quantum many-body methods is performed using the half-filled Hubbard model at weak coupling as testing grounds, with two numerically exact methods (diagrammatic and determinantal quantum Monte Carlo) serving as a benchmark.
Journal ArticleDOI
Tracking the Footprints of Spin Fluctuations: A Multi-Method, Multi-Messenger Study of the Two-Dimensional Hubbard Model
Thomas Schäfer,Nils Wentzell,Fedor Simkovic,Yuan-Yao He,Cornelia Hille,Marcel Klett,Christian Eckhardt,Behnam Arzhang,Viktor Harkov,François-Marie Le Régent,Alfred Kirsch,Yan Wang,Aaram J. Kim,Evgeny Kozik,E. A. Stepanov,Anna Kauch,Sabine Andergassen,Philipp Hansmann,Daniel Rohe,Y. M. Vilk,James P. F. LeBlanc,Shiwei Zhang,Andre-Marie Tremblay,Michel Ferrero,Olivier Parcollet,Antoine Georges +25 more
TL;DR: In this article, a comparative study of state-of-the-art quantum many-body methods using the half-filled Hubbard model at weak coupling was performed using several observables probing both quasiparticle properties and magnetic correlations, with two numerically exact methods (diagrammatic and determinantal quantum Monte Carlo) serving as a benchmark.
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How to read between the lines of electronic spectra: the diagnostics of fluctuations in strongly correlated electron systems.
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TL;DR: A comprehensive overview of the different approaches which have been recently developed and applied to identify the dominant twoparticle scattering processes controlling the shape of the one-particle spectral functions and, in some cases, of the physical response of the system is presented in this paper.
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Diagrammatic study of optical excitations in correlated systems
TL;DR: In this article, a simple procedure for incorporating antiferromagnetic or charge density wave fluctuations into dynamical mean field estimates of the optical conductivity and related susceptibilities was proposed.
References
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Book
Spin Fluctuations in Itinerant Electron Magnetism
Tôru Moriya,Yoshinori Takahashi +1 more
TL;DR: In this paper, a general theory of spin fluctuations and thermodynamical properties of itinerant electron magnets is developed, interpolating between the weakly and strongly ferromagnetic limits, and a unified expression is given for the Curie temperature and the physical meaning of the curie-Weiss magnetic susceptibility is discussed.