Autor: |
Messina, Fabrizio, Vella, Eleonora, Cannas, Marco, Boscaino, Roberto |
Rok vydání: |
2010 |
Předmět: |
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Druh dokumentu: |
Working Paper |
DOI: |
10.1103/PhysRevLett.105.116401 |
Popis: |
We studied the temperature dependence of the absorption coefficient of amorphous SiO$_2$ in the range from 8 to 17.5~eV obtained by Kramers-Kronig dispersion analysis of reflectivity spectra. We demonstrate the main excitonic resonance at 10.4~eV to feature a close Lorentzian shape red-shifting with increasing temperature. This provides a strong evidence of excitons being delocalized notwithstanding the structural disorder intrinsic to the amorphous system. Excitons turn out to be coupled to an average phonon mode of 83~meV energy. |
Databáze: |
arXiv |
Externí odkaz: |
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