2004/06/30 by Daniel Rohe, Walter Metzner · 1 citation
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Strong Light-Matter Interactions #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.115116
published as Phys. Rev. B 71, 115116 (2005) · 14 pages, 7 figures
openalex publication_date 2005/03/30 · arxiv created 2005/03/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze the interaction-induced renormalization of single-particle excitations in the two-dimensional Hubbard model at weak coupling using the Wick-ordered version of the functional renormalization group. The self-energy is computed for real frequencies by integrating a flow equation with renormalized two-particle interactions. In the vicinity of hot spots, that is, points where the Fermi surface intersects the umklapp surface, self-energy effects beyond the usual quasiparticle renormalizations and damping occur near instabilities of the normal, metallic phase. Strongly enhanced renormalized interactions between particles at different hot spots generate a pronounced low-energy peak in the imaginary part of the self-energy, leading to a pseudogaplike double-peak structure in the spectral function for single-particle excitations.