Raman Scattering Studies of Optical Phonons in GaAs/AlAs and GaAs/AlxGa1-xAs Superlattices
| Autor: | Guobao Li, He-Xiang Han, Zhuowei Wang |
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| Rok vydání: | 1991 |
| Předmět: |
Physics
Quantitative Biology::Biomolecules X-ray absorption spectroscopy Condensed matter physics Phonon Superlattice Degenerate energy levels Physics::Optics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter::Materials Science symbols.namesake Transverse plane Dispersion (optics) symbols Molecular symmetry Raman scattering |
| Zdroj: | Light Scattering in Semiconductor Structures and Superlattices ISBN: 9781489936974 |
| DOI: | 10.1007/978-1-4899-3695-0_7 |
| Popis: | It is weL.L. known from the phonon dispersion curves of bulk GaAs and AlAs that though their acoustic branches basically overlap, the optical branches do not. As a consequence, in GaAs/AlAs superlattices the acoustic phonon modes are the folded modes which can propagate through the whole superlattice, and the optical modes are the confined modes which are confined in GaAs and AlAs layers, respectively. (GaAs)n/(AlAs)n superlattices on (001)-oriented GaAs substrates have point group symmetry D2d- There are altogether n GaAs and n AlAs longitudinal optical (LO) and transverse optical (TO) confined modes; LOm and TOm with m = 1, 2, ..., n. The LOm modes belong to B2 (m odd) and A1 (m even) representations, respectively. Twofold degenerate TOm modes belong to the E representation. |
| Databáze: | OpenAIRE |
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