Effect of a thermal gradient on the charge-density-wave conduction-noise spectrum inNbSe3

Evidence that the well-defined charge-density-wave voltage oscillations seen in ${\mathrm{NbSe}}_3$ arise from the sample ends is obtained from experiments performed with the sample in a thermal gradient. Two fundamental frequencies arise in a gradient, one associated with each end. The current-frequency relationship is also altered in a manner consistent with the noise originating at the ends.