Ab initio calculations of the anisotropic dielectric tensor of GaAs/AlAs superlattices
|Title||Ab initio calculations of the anisotropic dielectric tensor of GaAs/AlAs superlattices|
|Publication Type||Palaiseau Article|
|Author Address|| |
Botti, S (Reprint Author), Ecole Polytech, CEA, CNRS, UMR 7642,Lab Solides Irradies, F-91128 Palaiseau, France. Ecole Polytech, CEA, CNRS, UMR 7642,Lab Solides Irradies, F-91128 Palaiseau, France. Univ Pavia, Dipartimento Fis A Volta, INFM, I-27100 Pavia, Italy.
|Botti, S, Vast, N, Reining, L, Olevano, V, Andreani, LC|
|Publisher||AMERICAN PHYSICAL SOC|
|Year of Publication||2002|
|Journal||Phys. Rev. Lett.|
The static dielectric properties of (001)(GaAs)(p)/(AlAs)(p) superlattices have been calculated as a function of their period p for 1 less than or equal to p less than or equal to 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.