Intrinsic quantum excitations of low temperature glasses.

Several puzzling regularities concerning the low temperature excitations of glasses are quantitatively explained by quantizing domain wall motions of the random first order glass transition theory. The density of excitations agrees with experiment and scales with the size of a dynamically coherent region at T(g), being about 200 molecules. The phonon coupling depends on the Lindemann ratio for vitrification yielding the observed universal relation l/lambda approximately 150 between phonon wavelength lambda and mean free path l. Multilevel behavior is predicted to occur in the temperature range of the thermal conductivity plateau.