Far-infrared photon absorption by phonons in ZnTe crystals
| Autor: | R. Brazis, D. Nausewicz |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Absorption spectroscopy
Condensed matter physics Chemistry Phonon Infrared Organic Chemistry Physics::Optics Neutron scattering Polarization (waves) Molecular physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Inorganic Chemistry Condensed Matter::Materials Science Dipole Far infrared Condensed Matter::Superconductivity Direct and indirect band gaps Electrical and Electronic Engineering Physical and Theoretical Chemistry Spectroscopy |
| Zdroj: | Optical Materials. 30:789-791 |
| ISSN: | 0925-3467 |
| DOI: | 10.1016/j.optmat.2007.02.040 |
| Popis: | One-phonon and two-phonon contributions to polarization are determined for ZnTe crystals in the frequency range of 1–4 THz using the existing experimental data on far-infrared absorption and neutron scattering. The two-phonon contribution in the 1.7 THz band is higher than the first-order absorption related to the ion dipole (TO mode) resonance (comparable in the 3–4 THz band). LA → TO phonon difference transitions are concluded to dominate in the 1.7 THz band, whereas TA → TO, TA → LO and mixed-mode A → O difference transitions are of primary importance in the 3–4 THz band. The contributions of the 2TA-overtone and other two-phonon-sum processes are comparatively weak. Matrix element squares for partial inter-phonon-band transitions are compared, and the photon–two-phonon coupling coefficients are estimated. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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