Two new effects associated with Fröhlich sliding-mode conductivity have been observed in Nb${\mathrm{Se}}_3$. First, nonlinear resistance is observed only after a well-defined threshold field is reached. Second, electric fields above the threshold result in noise in the potential difference across a current biased specimen. We interpret the threshold field as direct evidence of charge-density wave depinning and the noise as a result of charge-density wave motion.

• Received 15 March 1979

DOI:https://doi.org/10.1103/PhysRevLett.42.1423