Dynamical transition in sliding charge-density waves with quenched disorder.

We have studied numerically the dynamics of sliding charge-density waves ~CDW’s! in the presence of impurities in d51,2. The model considered exhibits a first-order dynamical transition at a critical driving force Fc between ‘‘rough’’ ~disorder dominated! (F,Fc) and ‘‘flat’’ (F.Fc) sliding phases where disorder is washed out by the external drive. The effective model for the sliding CDW’s in the presence of impurities can be mapped onto that of a magnetic flux line pinned by columnar defects and tilted by an applied field. The dynamical transition of sliding CDW’s corresponds to the transverse Meissner effect of the tilted flux line. @S0163-1829~96!02841-X#