Narrow-band "noise" and damping in NbSe₃

Abstract
We report the results of a Narrow-band "Noise" (NBN) study, in NbSe₃ for magnetic fields up to 19 T and temperatures as low as 15 K. The first result of this NBN study is the observation of the decrease of dJ_CDW/dv with decreasing temperatures for both transitions. We report also new values for the absolute value dJ_CDW/dv for both transitions, and the existence of a curvature of dJ_CDW/dv versus frequency, in low frequency range. We have interpreted the decrease of dJ_CDW/dv with temperatures in terms of Artemenko's theory which has been used in 1984 to explain the non-linear Hall effect in TaS₃. The total longitudinal current is given by [MATH], where the therm -AJ_CDW is a backward normal current flow due to the movin CDW. From the saturing value of dE/dv obtained in high electric field we have deducedet the total damping parameter [MATH] which is decreasing with temperature. Using data obtained under application of a magnetic field of 7 T and the Wonneberger's theory for the ac response of the collective mode, we have deduced the thermal variation of the bare phason damping coefficient [MATH]. We report that for [MATH] very close to the theoretical predictions of Takada, Wong and Holstein.