Propagation of plasmons across layers of GaAs-Ga1−xAlxAs superlattices

Abstract
The transformation from quasi‐two‐dimensional to three‐dimensional behavior of the free‐electron gas in GaAs‐Ga1−xAlxAs multiple quantum well structures was observed. This transformation corresponds to the establishment of well defined three‐dimensional plasmon modes measured by Raman scattering, which propagate across layers of an n‐type doped superlattice when the layer thicknesses are reduced to 20 Å or less. This type of behavior is consistent with the Kronig–Penney type model describing coupling between the wells and formation of energy minibands in a superlattice.