A statistical phase-slip model capable to describe fluctuations measured in charge density-wave systems

The charge transport via motion of charge density-waves (CDW) requires a co nversion of the charge carriers provided by the contacts (called single cha rge carriers or quasiparticles) into collective ones which are part of the CDW and vice versa. The conversion occurs via a so-called phase slip, i.e. phase fronts are added to or removed from the CDW, leading to a stress or s train in the CDW, respectively, which relaxes by a motion of the CDW. The d ynamics of the conversion process has a formative influence on the time-res olved signals measured at the contacts. We introduce a phase-slip model whi ch comprises the shape, the location, and the statistics of the intervals b etween successive phase-slip events and is able to describe noise phenomena often observed in CDW systems. The Fourier transform of the signal produce d by a single phase-slip event deduced from the well-established Fukujama-L ee-Rice model can be identified with the broad-band noise spectrum measured in experiment. The statistics which describes the sequence of these single events determines the narrow-band noise. We compare the noise spectra gain ed from the model with the ones obtained from our noise measurements on o-T aS3 samples. (C) 2001 Elsevier Science B.V. All rights reserved.