Low-temperature glass dynamics probed by optical dephasing measurements
| Autor: | L.R. Narasimhan, A. Elschner, Michael D. Fayer, Karl A. Littau, Y.S. Bai, Dee William Pack |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Range (particle radiation)
Photon Chemistry Dephasing Dynamics (mechanics) Biophysics Analytical chemistry Observable General Chemistry Chromophore Condensed Matter Physics Biochemistry Molecular physics Atomic and Molecular Physics and Optics Correlation function (statistical mechanics) Relaxation rate |
| Zdroj: | Journal of Luminescence. 45:49-53 |
| ISSN: | 0022-2313 |
| DOI: | 10.1016/0022-2313(90)90102-h |
| Popis: | Optical dephasing measurements in glasses are affected by dynamical processes which occur on a very broad range of time scales. The relaxation rate distribution of a glass can be measured by using a combination of experiments which operate on different characteristic timescales. A four-time correlation function treatment of the observables is used to extract the fluctuation rate distributions at short and long times from photon echo and time-dependent holeburning measurements at low temperatures (1.0 to 5.0 K). The temperature dependence of the optical dephasing is characteristic of the ‘two level system’ (TLS) structural dynamics of a glass. Evidence confirming that glasses have fixed potential surfaces at low temperature (the basis for the TLS model) is provided by temperature cycled holeburning measurements. Dephasing at higher temperatures ( ≈ 10 K) is shown to be a property of the glass, not from a local motion of the chromophore as previously believed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|