Wave-like and diffusive heat transport in a-SiO2 below 1 K
| Autor: | Peter Strehlow, Nutan Sampat, Michael Meissner |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Physics
Condensed matter physics Phonon Boundary (topology) Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Electronic Optical and Magnetic Materials Momentum symbols.namesake Condensed Matter::Superconductivity Boltzmann constant symbols Kinetic theory of gases Electrical and Electronic Engineering Absorption (electromagnetic radiation) Quantum tunnelling Energy (signal processing) |
| Zdroj: | Physica B: Condensed Matter. :302-304 |
| ISSN: | 0921-4526 |
| DOI: | 10.1016/0921-4526(95)00727-x |
| Popis: | Heat-pulse experiments have been performed in order to test the kinetic theory of phonons in glasses. Based on the coupled Boltzmann equations for phonons and localized tunneling systems field equations for the phonon energy, the tunneling state energy and the phonon momentum have been derived. It is shown that the solution of these symmetric hyperbolic field equations for given boundary and initial values of heat-pulse measurements are in excellent agreement with new experimental data obtained in vitreous silica below 1 K. In the thermodynamic theory presented, the specific heat of glasses is not time dependent explicitly but depends on time via temperature only. Moreover, the theory predicts a new pulse propagation at very short times reflecting a wave-like energy transport due to the absorption and emission of phonons by fast relaxing tunneling states. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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