Spectral properties of quasi-one-dimensional conductors with a finite transverse band dispersion

摘要

We determine the one-particle spectral function and the corresponding derived quantities for the conducting chain lattice with finite inter-chain hopping t(perpendicular to) and three-dimensional long-range Coulomb electron-electron interaction. The standard G(0)W(0) approximation is used. It is shown that, due to the optical character of the anisotropic plasmon dispersion caused by the finite t(perpendicular to), a low energy quasi-particle delta-peak appears in the spectral function in addition to the hump present at energies of the order of the plasmon energy. Particular attention is devoted to the continuous crossover from the non-Fermi liquid regime to the Fermi liquid regime with increasing t(perpendicular to). It is shown that the spectral weight of the hump transfers to the quasi-particle as the optical gap in the plasmon dispersion increases together with t(perpendicular to), with the quasi-particle residuum Z behaving like -(ln t(perpendicular to))(-1) in the limit t(perpendicular to) -> 0. Our approach is appropriate for the wide range of energy scales given by the plasmon energy and the width of the conduction band, and is complementary to the Luttinger liquid techniques that are limited to the low energy regime close to the Fermi surface.