Breakdown of the Landau-Fermi liquid in two dimensions due to umklapp scattering
Breakdown of the Landau-Fermi liquid in two dimensions due to umklapp scattering
We study the renormalization-group (RG) flow of interactions in the two-dimensional ${t\ensuremath{-}t}^{\ensuremath{'}}$ Hubbard model near half-filling in an N-patch representation of the whole Fermi surface. Starting from weak to intermediate couplings the flows are to strong coupling, with different characters depending on the choice of parameters. In a large parameter …