2010/05/31 by Andreas Eberlein, Walter Metzner · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Excited state #Gravitational singularity #Invariant (physics) #Iron-based superconductors research #Mathematical physics #Parametrization (atmospheric modeling) #Physics #Physics of Superconductivity and Magnetism #Quantum electrodynamics #Quantum mechanics #Radiative transfer #Renormalization #Renormalization group #Singlet state #Superconductivity #Vertex (graph theory) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1143/ptp.124.471
published as Prog.Theor.Phys.124:471-491,2010 · 21 pages, 5 figures
arxiv created 2010/07/22 · openalex publication_date 2010/09/01 · arxiv updated 2011/01/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyze general properties of the effective Nambu two-particle vertex and its renormalization group flow in a spin-singlet superconductor. In a fully spin-rotation invariant form the Nambu vertex can be expressed by only three distinct components. Solving exactly the flow of a mean-field model with reduced BCS and forward scattering interactions, we gain insight into the singularities in the momentum and energy dependences of the vertex at and below the critical energy scale for superconductivity. Using a decomposition of the vertex in various interaction channels, we manage to isolate singular momentum and energy dependences in only one momentum and energy variable for each term, such that the singularities can be efficiently parametrized.