Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.37: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Fermionic renormalization group flow into phases with broken discrete symmetry: charge-density wave mean-field model — •Roland Gersch1, Carsten Honerkamp2, Daniel Rohe3, and Walter Metzner1 — 1Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart — 2Institut für Theoretische Physik, Uni Würzburg, Am Hubland, 97074 Würzburg — 3Ecole Polytechnique - CPhT, F91128 Palaiseau Cedex, France
We generalize the application of the functional renormalization group (fRG) method for the fermionic flow into the symmetry-broken phase to finite temperatures. We apply the scheme to the case of a broken discrete symmetry: the charge-density wave (CDW) mean-field model at half filling. We show how an arbitrarily small initial CDW order parameter starts to grow at the CDW instability and how it flows to the correct final value, suppressing the divergence of the effective interaction in the fRG flow. The effective interaction peaks at the instability and saturates at low energy scales. The relation to the mean-field treatment and the prospects of the new method are discussed.