title: Coherence of elementary excitations in a disordered electron system.
abstract: The localization properties of the single-particle and collective electron excitations were investigated in the intentionally disordered GaAs/AlGaAs superlattices by weak-field magnetoresistance and Raman scattering. The localization length of the individual electron was found to be considerably larger than that of the collective excitations. This suggests that the disorder has a weaker effect on the electrons than on their collective motion and that the interaction which gives rise to the collective effects increases localization.
authors.affiliation: Instituto de Fisica de São Carlos, Universidade de São Paulo, Brazil.
authors.forename: Yu A
authors.initials: YA
authors.lastname: Pusep
authors.forename: M B
authors.initials: MB
authors.lastname: Ribeiro
authors.forename: V E
authors.initials: VE
authors.lastname: Carrasco
authors.forename: G
authors.initials: G
authors.lastname: Zanelatto
authors.forename: J C
authors.initials: JC
authors.lastname: Galzerani