Universality in glassy low-temperature physics

Institut für Theoretische Physik, Universität Heidelberg Philosophenweg 19, 69120 Heidelberg, Germany

Received: 13 November 2002
Accepted: 7 March 2003

Abstract

We propose a microscopic translationally invariant glass model which exhibits two-level tunneling systems, and shows the salient low-temperature anomalies of glassy systems. Results so far obtained are in good accord with experiment. Qualitative universality is due to the collective origin of the glassy potential energy landscape. However, we obtain a simple explanation also for the mysterious so-called quantitative universality that manifests itself, e.g., in the unusually weak dependence of values for the internal friction plateau on substance or system parameters.