Sliding charge-density waves: A numerical study

Numerical results are presented for the behavior of a one-dimensional, classical, deformable charge-density wave pinned by random impurities in applied electric fields below and close to the threshold field for sliding. We discuss the properties of metastable states and show how they can give rise to hysteresis and memory. Both the linear and nonlinear response functions are enhanced at low frequencies. The enhancement of the dielectric response is consistent with the existence of a low-frequency cusp in infinite systems. At fields just exceeding threshold, we find very long relaxation times for the system to reach dynamic equilibrium, with strong broadband noise produced as a transient effect. The effect of thermal hopping at low temperatures is briefly discussed.