title: Ab Initio calculations of the anisotropic dielectric tensor of GaAs/AlAs superlattices.
abstract: The static dielectric properties of (001)(GaAs)(p)/(AlAs)(p) superlattices have been calculated as a function of their period p for 1< or = p < or =12, starting from density-functional theory. The interplay between quantum confinement and local field effects is shown to be crucial. For light polarized in the growth direction it leads to the otherwise surprising justification of the use of a classical effective medium theory, even for the smallest periods. Only the inclusion of both contributions allows in ab initio and in semiempirical calculations to reproduce the experimentally observed birefringence.
authors.affiliation: Laboratoire des Solides Irradiés, UMR 7642 CNRS-CEA, Ecole Polytechnique, F-91128 Palaiseau, France.
authors.forename: Silvana
authors.initials: S
authors.lastname: Botti
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vast
authors.forename: Lucia
authors.initials: L
authors.lastname: Reining
authors.forename: Valerio
authors.initials: V
authors.lastname: Olevano
authors.forename: Lucio Claudio
authors.initials: LC
authors.lastname: Andreani