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Correlated starting points for the functional renormalization group

Autor(en)
N. Wentzell, C. Taranto, A. Katanin, A. Toschi, S. Andergassen
Abstrakt

We present a general frame to extend functional renormalization group (fRG) based computational schemes by using an exactly solvable interacting reference problem as starting point for the RG flow. The systematic expansion around this solution accounts for a nonperturbative inclusion of correlations. Introducing auxiliary fermionic fields by means of a Hubbard-Stratonovich transformation, we derive the flow equations for the auxiliary fields and determine the relation to the conventional weak-coupling truncation of the hierarchy of flow equations. As a specific example we consider the dynamical mean field theory (DMFT) solution as reference system, and discuss the relation to the recently introduced DMF(2)RG and the dual-fermion formalism.

Organisation(en)
Quantenoptik, Quantennanophysik und Quanteninformation
Externe Organisation(en)
Technische Universität Wien, Ural Federal University, Russian Academy of Sciences, Eberhard Karls Universität Tübingen
Journal
Physical Review B
Band
91
Anzahl der Seiten
11
ISSN
1098-0121
DOI
https://doi.org/10.1103/PhysRevB.91.045120
Publikationsdatum
01-2015
Peer-reviewed
Ja
ÖFOS 2012
103019 Mathematische Physik, 103009 Festkörperphysik
Schlagwörter
ASJC Scopus Sachgebiete
Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/ae19cee4-4399-4a6b-a850-c8f03d9f0b98