Evidence for the onset of Fröhlich-mode conductivity inK0.30MoO3

We have investigated novel nonlinear conduction properties in ${\mathrm{K}}_{0.30}$ ${\mathrm{MoO}}_3$ at temperatures below 40 K. At threshold fields of several V/cm the current is observed to increase sharply by 8–10 orders of magnitude. The transition into the highly conducting state is characterized by an exponential I-V characteristic which becomes bistable at high currents. Narrow-band noise is observed with a linear frequency to current dependence over 5 orders of magnitude. The results are discussed in terms of a model describing the onset of rigid charge-density-wave motion at low temperatures and high fields.