Abstract
We analyze the particle-hole symmetric two-dimensional Hubbard model on a square lattice starting from weak-to-moderate couplings by means of the field-theoretical renormalization group approach up to two-loop order. This method is essential in order to evaluate the effect of the momentum-resolved anomalous dimension which arises in the normal phase of this model on the corresponding low-energy single-particle excitations. As a result, we find important indications pointing to the existence of a non-Fermi-liquid (NFL) regime at temperature displaying a truncated Fermi surface (FS) for a doping range exactly in between the well-known antiferromagnetic insulating and the -wave singlet superconducting phases. This NFL evolves as a function of doping into a correlated metal with a large FS before the -wave pairing susceptibility finally produces the dominant instability in the low-energy limit.
2 More- Received 15 May 2008
DOI:https://doi.org/10.1103/PhysRevB.78.125114
©2008 American Physical Society