Physical review. B, Condensed matter
Critical indices in a d=1 filled-band Fermi system
Federico Bonetto, Vieri Mastropietro
Abstract
By renormalization-group methods we obtain nonperturbative results about a $d=1$ system of interacting spinless fermions in a periodic potential when the conduction band is filled. Both the strength of the interaction and the amplitude of the periodic potential are assumed to be small. We determine that the large-distance asymptotic behavior of the two-point Schwinger function is anomalous and described by two critical indices, explicitly computed by convergent series, related to the renormalization of the spectral gap and of the discontinuity at the Fermi surface.