Coherence of elementary excitations in a disordered electron system

• Published in: Physical review letters Vol. 94; no. 13; pp. 136407.1 - 136407.4
• Main Authors: PUSEP, Yu. A, RIBEIRO, M. B, CARRASCO, V. E, ZANELATTO, G, GALZERANI, J. C
• Format: Journal Article
• Language: English
• Published: Ridge, NY American Physical Society 08-04-2005
• Subjects: Collective excitations (including excitons, polarons, plasmons and other charge-density excitations); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Surface and interface electron states; Aluminium arsenides; Raman spectra; Disordered systems; Gallium arsenides; Localized states; Superlattices; Coherence; Plasmons; Elementary excitation; Low field; Magnetoresistance
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.94.136407

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.