Complex energy relaxation at very low temperature in linear chain conductors with CDW's or SDW's

We present four distinct features of the energy relaxation after switching off a small heat perturbation at very low temperatures in charge density wave- and spin density wave systems which demonstrate the glassy nature of their ground state. The nonexponential decay shows the evolving “aging effect” with a crossover between a non-equilibrium and a thermodynamical equilibrium. This relaxation is thermally activated with the activation energy of ∼1–2 K, depending also on the duration of the perturbation.