Abstract

In the last two decades the dynamics of glasses has been a field of great interest. In order to explain the dynamical properties of glasses the two-level-system model has been proposed. In this model an atom, or group of atoms, can access two potential minima separated by a barrier. Phonon-assisted-tunneling between the two minima of this asymmetric double well potential represents a jump between two different local glass structures. These double well potentials are referred to as two-level-systems (TLS). In the standard TLS-model the potentials do not change in time. The intrinsic disorder of the glass provides a wide range of asymmetries and a broad distribution of transition rates. Consequently the dynamics of the glass takes place over a broad range of time scales.

© 1992 Optical Society of America