STATISTICAL-MODEL FOR TIME-DEPENDENT TRANSPORT IN CHARGE-DENSITY-WAVESYSTEMS

Quasi-one-dimensional metals show a metal-semiconductor transition at a certain temperature. Below the so-called Peierls temperature, charge -density waves are developing within these metals. The resulting colle ctive electronic state is responsible for unusual transport properties , such as nonlinear current-voltage characteristics with a threshold a nd current-voltage oscillations above threshold accompanied by broad-b and noise. Current-voltage oscillations are thought to originate from charge-density waves when they begin to contribute to charge transport . The current-voltage characteristic is explained by the transition of electrons from the single-particle state to the collective electron s tate and vice versa (phase-slip acts). The current-voltage oscillation s, however, are supposed to be generated in the bulk due to interactio n with impurities. The purpose of the present Letter is to discuss a s imple statistical model which describes the time-dependent process at the interface between charge-density waves and single-particle electro ns. Our model can explain the transport phenomena that are mentioned a bove. We suppose the transport in the bulk to be diffusive. (C) 1998 E lsevier Science B.V.