Glass transition in the charge density wave system K${}_{0.3}$MoO${}_3$

Low frequency dielectric spectroscopy and thermally stimulated discharge measurements of charge density wave (CDW) system K${}_{0.3}$MoO${}_3$ are presented. Below 80 K two distinct relaxational processes are observed, which freeze at finite temperatures bearing close resemblance to the phenomenology of the dielectric response of glasses. We compare our results to the case of o-TaS${}_3$ in which the glass transition on the level of CDW superstructure has been recently reported\cite{Star02} and discuss the possibility that it is a universal feature of CDW systems.