Self-energy flows in the two-dimensional repulsive Hubbard model

• Verfasst von: Giering, Kay-Uwe [VerfasserIn]
• Verfasst von: Salmhofer, Manfred [VerfasserIn]
• Titel: Self-energy flows in the two-dimensional repulsive Hubbard model
• Verf.angabe: Kay-Uwe Giering and Manfred Salmhofer
• Fussnoten: Gesehen am 11.06.2018
• Titel Quelle: Enthalten in: Physical review / B
• Jahr Quelle: 2012
• Band/Heft Quelle: 86(2012,24) Artikel-Nummer 245122, 20 Seiten
• ISSN Quelle: 1550-235X
• DOI: doi:10.1103/PhysRevB.86.245122
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 157621463X

Abstract

We study the two-dimensional repulsive Hubbard model by functional renormalization group methods, using our recently proposed channel decomposition of the interaction vertex. The main technical advance of this work is that we calculate the full Matsubara frequency dependence of the self-energy and the interaction vertex in the whole frequency range without simplifying assumptions on its functional form, and that the effects of the self-energy are fully taken into account in the equations for the flow of the two-body vertex function. At Van Hove filling, we find that the Fermi-surface deformations remain small at fixed particle density and have a minor impact on the structure of the interaction vertex. The frequency dependence of the self-energy, however, turns out to be important, especially at a transition from ferromagnetism to d-wave superconductivity. We determine non-Fermi-liquid exponents at this transition point.