Berlin 2008 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 14: Statistical physics II (general)
DY 14.7: Vortrag
Dienstag, 26. Februar 2008, 15:45–16:00, MA 004
Non-Fermi liquid regime in the 2D Hubbard model at weak-to-moderate coupling — •Hermann Freire1, Eberth Correa2, and Alvaro Ferraz2 — 1Max-Planck-Institute for Solid State Research, D-70569 Stuttgart, Germany — 2International Center for Condensed Matter Physics, Universidade de Brasilia, Caixa Postal 04667, 70910-900 Brasilia-DF, Brazil
We analyze the two-dimensional Hubbard model on a square lattice at weak-to-moderate coupling by implementing the functional field-theoretical renormalization group (RG) up to two-loop order. This approach is essential to evaluate the effect of the anomalous dimension induced by interactions on the low-energy single-particle excitations. As a result, we find evidence of a non-Fermi liquid (NFL) regime near half-filling before the dx2−y2-wave singlet superconducting instability becomes dominant. To characterize the nature of this NFL phase, we perform a systematic two-loop RG study of several susceptibilities of interest in the model.