Abstract
Phonons in parabolic-quantum-well structures fabricated with semiconductor alloys are studied. We calculate frequencies, displacement patterns, and densities of states for lattice vibrations in a (GaAs(As(001) superlattice where the GaAs layers are replaced by a mixed crystal As with Al fraction varying quadratically with atomic layer s. The influence of disorder, composition, and the two-mode behavior of optical phonons are investigated within a random-element-isodisplacement model, generalized to layered structures with arbitrary composition profiles.
- Received 27 May 1993
DOI:https://doi.org/10.1103/PhysRevB.48.14667
©1993 American Physical Society