Uniform electron gas and simple metals
The simplest model system representing condensed matter is the homogeneous electron gas, in which the nuclei are replaced by a uniform positively charged background. This system is completely specified by the density n (or rs, which is the average distance between electrons) and the spin density n↑ – n↓ or the polarization ζ = (n↑ – n↓)/n. The homogeneous gas illustrates the problems associated with interacting electrons in condensed matter and is a prelude to the electronic structure of matter, which is governed by the combined effects of nuclei and electron interaction.
The homogeneous electron gas is the simplest system for illustrating key properties of interacting electrons and characteristic ...