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Dynamics of Nonlinear Tenuous Structures

  • A. Jagannathan
  • R. Orbach
  • O. Entin-Wohlman
Conference paper
Part of the Springer Series in Synergetics book series (SSSYN, volume 43)

Abstract

The vibrational dynamics of tenuous structures is developed using extended and localized states. A phonon-fracton model is used for explicit computations. It is shown that the localized states can contribute to thermal transport via hopping processes, assisted by absorption of extended state vibrations. This “phonon assisted-fracton hopping” is the vibrational analog of Mott’s variable range hopping contribution to electical conductivity. Comparison with thermal conductivity experiments on amorphous materials allows an estimate of the magnitude of the anharmonicity coefficient. It is found to be (roughly) two orders of magnitude larger than the acoustic limit. This enhancement is attributed to the “openness” of the geometry for fracton excitations, and could have profound effects on the vibrational and conformational excitations of tenuous structures.

Keywords

Silica Aerogel Thermal Transport Vibrational Excitation Localization Length Plateau Temperature 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin, Heidelberg 1989

Authors and Affiliations

  • A. Jagannathan
    • 1
  • R. Orbach
    • 1
  • O. Entin-Wohlman
    • 1
    • 2
  1. 1.Department of PhysicsUniversity of CaliforniaLos AngelesUSA
  2. 2.School of Physics and AstronomyTel Aviv UniversityRamat Aviv, Tel AvivIsrael

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