Broad band noise and stochastic resonance in the CDW conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002)

We have investigated nonlinear characteristics and broad band noise in the quasi-one dimensional charge-density-wave conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002) When the amplitude of a bipolar rectangular voltage pulse excitation is modulated by adding a white noise perturbation, the average pulse amplitude is smaller than the unperturbed one and shows a non monotonous behaviour when the pulse amplitude is increased. Our findings suggest that coupling between internal broad band noise and external white noise may lead to an increase of phase coherence of the charge-density-wave.