Noise Measurements on CDW Systems Compared to a Statistical Model for the Dynamics Involved

Charge-density waves, a collective electronic state, exhibit a variety of unusual transport properties. One finds nonlinear current-voltage characteristics with a pronounced threshold. Above threshold, narrow-band noise as well as broad-band noise are observed. The form of the current-voltage characteristic has been explained by the conversion of electrons between the single-particle and collective-particle state (phase-slip events). The present contribution introduces a statistical phase-slip model for the time-dependent transport properties. Within this model we interpret the broad-band noise as the Fourier transform of one phase-slip and the narrow-band noise as Fourier transform of the statistics of subsequent phase slips.