DISCRETE FLUCTUATORS AND BROAD-BAND NOISE IN THE CHARGE-DENSITY-WAVE IN NBSE3

In small samples of NbSe3 the broadband noise of the sliding charge-density wave (CDW) can be partially resolved into two-state and multistate fluctuators, which show strong sensitivity to the bias current and temperature. Explicit violations of detailed balance appear. Near the threshold bias for sliding, intermittent periods of noise occur, indicating that some or all of the sample fluctuates between the pinned and sliding states. The behavior of the discrete fluctuators under a variety of time-dependent bias conditions indicates that some particular configurations are available for the CDW in both sliding and pinned states, but with slower dynamics in the pinned state. The results are consistent with a model in which the noise comes from collective rearrangements of defects in the CDW.