Temperature Dependence of the Far-Infrared Absorption Spectrum in Amorphous Dielectrics

Abstract

A study of the temperature dependence of the absorption coefficient in amorphous dielectrics below 10 ${\mathrm{cm}}^{\ensuremath{-}1}$ has enabled us to identify two level configurations from thermal population changes. We also find that the anomalous low-frequency modes in glasses consist of widely spaced manifolds of energy levels.