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