Metastability and hysteresis in the low-frequency dielectric response of the charge-density wave in K0.3MoO3.

Abstract

We have investigated the dielectric response of the charge-density wave (CDW) in ${\mathrm{K}}_{0.3}$${\mathrm{MoO}}_{3}$ at temperatures between 30 and 90 K, a temperature regime where the effects of metastable CDW states become the dominant influence on the low-frequency CDW behavior. We observe temperature-quenched metastable CDW states at temperatures below 90 K which are erased by biasing above the threshold field for nonlinear conductivity. We have characterized the density of states for the metastable CDW configuration through measurements of \ensuremath{\epsilon}(\ensuremath{\omega}). Further, we observe in bias-dependent dielectric measurements the effects of long-lived metastable CDW states in the pinned regime over the whole temperature range, as well as very long relaxation times in the sliding state at low temperatures.