Pseudogap at hot spots in the twodimensional Hubbard model at weak coupling
Abstract
We analyze the interactioninduced renormalization of singleparticle excitations in the twodimensional Hubbard model at weak coupling using the Wickordered version of the functional renormalization group. The selfenergy is computed for real frequencies by integrating a flow equation with renormalized twoparticle interactions. In the vicinity of hot spots, that is, points where the Fermi surface intersects the umklapp surface, selfenergy 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 lowenergy peak in the imaginary part of the selfenergy, leading to a pseudogaplike doublepeak structure in the spectral function for singleparticle excitations.
 Publication:

Physical Review B
 Pub Date:
 March 2005
 DOI:
 10.1103/PhysRevB.71.115116
 arXiv:
 arXiv:condmat/0406164
 Bibcode:
 2005PhRvB..71k5116R
 Keywords:

 71.10.Fd;
 71.27.+a;
 71.10.Hf;
 Lattice fermion models;
 Strongly correlated electron systems;
 heavy fermions;
 NonFermiliquid ground states electron phase diagrams and phase transitions in model systems;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 14 pages, 7 figures