Evidence for bulk ‘‘narrow-band noise’’ inNbSe3: Thermal-gradient studies

Current oscillations or ‘‘narrow-band noise’’ peaks associated with nonlinear charge-density wave conduction in ${\mathrm{NbSe}}_3$ are studied in the presence of a thermal gradient. Multiple splitting of the spectral noise peaks are observed for both Peierls transitions, suggesting the formation of velocity-coherent regions having a minimum length of ≊100 μm. These results are consistent with narrow-band-noise models in which current oscillations result from bulk interaction between the sliding charge-density wave and the impurity pinning potential.