Functional renormalization group for commensurate antiferromagnets: Beyond the mean-field picture

Stefan A. Maier, Andreas Eberlein, Carsten Honerkamp

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

We present a functional renormalization group (fRG) formalism for interacting fermions on lattices that captures the flow into states with commensurate spin-density-wave order. During the flow, the growth of the order parameter is fed back into the flow of the interactions and all modes can be integrated out. This extends previous fRG flows in the symmetric phase that run into a divergence at a nonzero RG scale, i.e., that have to be stopped at the ordering scale. We use the corresponding Ward identity to check the accuracy of the results. We apply our method to a model with two Fermi pockets that have perfect particle-hole nesting. The results obtained from the fRG are compared with those in random-phase approximation.

Original languageEnglish
Article number035140
Number of pages22
JournalPhysical Review B
Volume90
Issue number3
DOIs
Publication statusPublished - 29 Jul 2014
Externally publishedYes

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