The two-dimensional Hubbard model with a single spin-up electron interacting with a finite density of spin-down electrons is studied by use of the quantum Monte Carlo technique, the standard second-order perturbation theory and a very good variational wave function introduced recently by Edwards. We also present a new conjugate gradient scheme for the evaluation of this variational state. We performed simulations up to 242 sites at U/t = 4 reaching the zero-temperature properties with no ''fermion-sign problem'' and found a surprisingly good accuracy of the Edwards state at low density or low doping. The conjugate gradient method was then applied to the system up to 3698 sites and infinite U. Fermi-liquid theory seems to remain stable in two dimensions for all cases studied with the exception of the half-filling case where a Luttinger-like behavior survives in the Hubbard model, yielding a vanishing quasiparticle weight in the thermodynamic limit.
|Titolo:||NUMERICAL EVIDENCE OF LUTTINGER-LIQUID AND FERMI-LIQUID BEHAVIOR IN THE 2-DIMENSIONAL HUBBARD-MODEL|
|Rivista:||PHYSICAL REVIEW. B, CONDENSED MATTER|
|Data di pubblicazione:||1994|
|Digital Object Identifier (DOI):||10.1103/PhysRevB.49.12373|
|Appare nelle tipologie:||1.1 Journal article|