Low-temperature divergence of the polarizability in charge density wave compounds

Abstract
We have found that the dielectric constant of the quasi one-dimensional conductors with a charge-density wave (CDW) shows a peak in the low temperature range. This peak can only be detected at frequencies below 100 kHz and its position is shifted at lower temperatures with decreasing frequencies. In the same temperature range the relaxation time grows drastically. These features are usually characteristic of a transition to a glassy-like state in systems with some disorder. We suggest a qualitative mode1 which describes the behavior of CDW near this transition. These results provide a direct experimental evidence that with decreasing temperature the CDW turns into a glassy-like state which consists of large enough domains frozen in the CDW electron crystal. This state is characterized b many metastable realizations, hoping conductivity, non-exponential relaxation of perturbations, very large relaxation time and aging effects, features which are indeed observed in experiments.