Many-body local fields and quasiparticle renormalization effects in two-dimensional electronic systems

Abstract

We have developed a new microscopic approach designed to study the effects of the electron-electron interaction on various normal state quasiparticle properties in two-dimensional electronic systems. In our treatment the effects of charge and spin fluctuation induced vertex corrections are explicitly accounted for through the introduction of appropriate Hubbard-type many-body local field corrections. Our analysis is based on a novel self-consistent determination of the many-body local fields in two-dimensional systems for which some useful and new exact results have been derived. Although quite general our theory finds its natural application in the calculation of the quasiparticle effective mass and the anomalous Landé g-factor in silicon inversion layers, which display a pronounced dependence on the carrier density, a clear signal of interaction effects. It will be shown that, within the Landau theory of the Fermi liquids, the concomitant inclusion of previously neglected many-body effects associated with charge and spin fluctuation induced vertex corrections is crucial in attaining a satisfactory description of the observed phenomena.