Anomalous Dielectric Dispersion in Glasses at Low Temperatures

Abstract

We have found a strong temperature dependence in the dielectric constant of three different glasses below 5 K, which we ascribe to the low-energy excitations of the amorphous state. From our data we can determine the electrical dipole moment associated with these excitations, which gives rise to resonant absorption of electromagnetic waves. The corresponding absorption coefficient is expected to saturate at electromagnetic intensities above a few milliwatts per square centimeter.