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 language | English |
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Article number | 035140 |
Number of pages | 22 |
Journal | Physical Review B |
Volume | 90 |
Issue number | 3 |
DOIs | |
Publication status | Published - 29 Jul 2014 |
Externally published | Yes |