Electron Interaction in Metals

L. F. Novikov

Gordon Baym

Superconductivity arises from a very complicated set of interactions between the electrons in a metal. This chapter considers a very simplified model of the interaction of a pair of electrons in a metal, it is an instructive example of how quantum mechanics works and the main features of this model are at the starting point of the modern theory of superconductivity. In a metal one has a repulsive Coulomb interaction between the electrons, together with an attractive interaction between the electrons and ions. The total interaction between any two electrons is a composite of this attraction plus the Coulomb repulsion. In some metals, this total interaction is attractive for electrons near the Fermi surface.

Assa Auerbach

Sudip Chakravarty, Lan Yin, Elihu Abrahams

We show that a non-Fermi-liquid state of interacting electrons in two dimensions is stable in the presence of disorder and is a perfect conductor, provided the interactions are sufficiently strong. Otherwise, the disorder leads to localization as in the case of noninteracting electrons. This conclusion is established by examining the replica field theory in the weak-disorder limit, but in the presence of arbitrary electron-electron interaction. Thus, a disordered two-dimensional metal is a perfect metal, but not a Fermi liquid.

Jun Kondo

John W. Wilkins

Contents: Effective electron-electron interaction in metals; Electron-phonon interaction; Fermi liquid theory.