2011/11/29 by Christoph Husemann, Kay-Uwe Giering, Manfred Salmhofer
Materials Science · Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Combinatorics #Iron-based superconductors research #Mathematical physics #Mathematics #Momentum (technical analysis) #Physics #Physics of Superconductivity and Magnetism #Renormalization #Vertex (graph theory) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.85.075121
published as Phys. Rev. B 85, 075121 (2012) · 37 pages, 11 figures
arxiv created 2011/11/29 · openalex publication_date 2012/02/21 · arxiv updated 2012/03/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a functional renormalization group calculation for the two-dimensional (t,t^\ensuremath')-Hubbard model at Van Hove filling. Using a channel decomposition we describe the momentum and frequency dependence of the vertex function in the normal phase. Compared to previous studies that neglect frequency dependencies we find higher pseudocritical scales and a smaller region of d-wave superconductivity. A large contribution to the effective interaction is given by a forward-scattering process with finite frequency exchange. We test different frequency parametrizations and in a second calculation include the frequency dependence of the imaginary self-energy. We also generalize the channel decomposition to frequency-dependent fermion-boson vertex functions.