Ab-initio calculation of optical absorption in semiconductors: A density-matrix description
Abstract
We show how to describe Coulomb renormalization effects and dielectric screening in semiconductors and semiconductor nanostructures within a first-principles density-matrix description. Those dynamic variables and approximation schemes which are required for a proper description of dielectric screening are identified. It is shown that within the random-phase approximation the direct Coulomb interactions become screened, with static screening being a good approximation, whereas the electron-hole exchange interactions remain unscreened. Differences and similarities of our results with those obtained from a corresponding GW approximation and Bethe-Salpeter equation Green's function analysis are discussed.
Keywords
Cite
@article{arxiv.cond-mat/0108325,
title = {Ab-initio calculation of optical absorption in semiconductors: A density-matrix description},
author = {Ulrich Hohenester},
journal= {arXiv preprint arXiv:cond-mat/0108325},
year = {2009}
}
Comments
10 pages, to be published in Physical Review B