Archivi J. Phys. A (2007)

Author Vieri Mastropietro

Title Absence of logarithmic divergences in the spin and charge density correlations of the $1d$ Hubbard model

Abstract We perform a rigorous computation of the spin and charge density correlations of the 1d repulsive Hubbard model at weak coupling, focusing on the properties of the Fourier transform at momentum 0 and 2 p_F, if $p_F$ is the Fermi momentum. We prove that the interaction changes the singularity at 2 p_F (the discontinuity in the derivative becomes a power law singularity) while the singularity at 0 is essentially unchanged. Our results show that the logarithmic divergences at zero momentum recently found in a recent ppaer by Ferraz et al., which would be in contrast with Luttinger liquid behaviour, are indeed spurious.

Keywords Hubbard model, response functions, Ward Identities

Vieri Mastropietro
Last modified: Sat Feb 18 14:42:23 CET 2007