2000/10/20 by V. Zlatic, V. Zlatić, Berislav Horvatić +8 · 1 citation
Physics and Astronomy · #Brillouin zone #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Electron #Fermi Gamma-ray Space Telescope #Fermi surface #Function (biology) #Hubbard model #Mathematical physics #Perturbation (astronomy) #Perturbation theory (quantum mechanics) #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum electrodynamics #Quantum mechanics #Space (punctuation) #Spectral function #Spectral gap #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.63.035104
17 pages, 11 Postscript figures, Phys. Rev. B, accepted
arxiv created 2000/10/20 · openalex publication_date 2000/12/29 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We develop an efficient method to calculate the third-order corrections to the self-energy of the hole-doped two-dimensional Hubbard model in space-time representation. Using the Dyson equation we evaluate the renormalized spectral function in various parts of the Brillouin zone and find significant modifications with respect to the second-order theory even for rather small values of the coupling constant U. The spectral function becomes unphysical for U\ensuremath≃W, where W is the half-width of the conduction band. Close to the Fermi surface and for U<W, the single-particle spectral weight is reduced in a finite energy interval around the Fermi energy. The increase of U opens a gap between the occupied and unoccupied parts of the spectral function.