  There has been a recent renewal of interest in charge-density-wave (CDW)
phenomena, primarily driven by the emergence of two-dimensional (2D) layered
CDW materials, such as 1T-TaS2, characterized by very high transition
temperatures to CDW phases. In the extensively studied classical bulk CDW
materials with quasi-1D crystal structure, the charge carrier transport
exhibits intriguing sliding behavior, which reveals itself in the frequency
domain as "narrowband" and "broadband" noise. Despite the increasing attention
on physics of 2D CDWs, there have been few reports of CDW sliding, specifically
in quasi-2D rare-earth tritellurides and none on the noise in any of 2D CDW
systems. Here we report the results of low-frequency noise (LFN) measurements
on 1T-TaS2 thin films - archetypal 2D CDW systems, as they are driven from the
nearly commensurate (NC) to incommensurate (IC) CDW phases by voltage and
temperature stimuli. We have found that noise in 1T-TaS2 devices has two
pronounced maxima at the bias voltages, which correspond to the onset of CDW
sliding and the NC-to-IC phase transition. We observed unusual Lorentzian noise
features and exceptionally strong noise dependence on electric bias and
temperature. We argue that LFN in 2D CDW systems has unique physical origin,
different from known fundamental noise types. The specifics of LFN in 2D CDW
materials can be explained by invoking the concept of interacting discrete
fluctuators in the NC-CDW phase. Noise spectroscopy can serve as a useful tool
for understanding electronic transport phenomena in 2D CDW materials
characterized by coexistence of different phases and strong CDW pinning.
