COLLECTIVE DYNAMICS IN A MODEL OF SLIDING CHARGE-DENSITY WAVES .1. CRITICAL-BEHAVIOR

The dynamics and critical phenomena of the depinning transition in cha rge-density-wave (CDW) systems are explored, primarily through simulat ions of an automaton model that we have developed to characterize the essential features of the standard Fukuyama-Lee-Rice (FLR) treatment o f CDW's. We first provide an overview of the dynamics of the class of FLR models, and then derive our automaton model. We report results of simulations above and below the depinning transition, focusing primari ly on the behavior of the CDW velocity above threshold and the growth of dynamic correlations on both sides of the transition. The critical exponent zeta describing the scaling of the CDW velocity is estimated in d = 1, 2, and 3, in agreement with estimates of zeta from simulatio ns of related CDW models and a recent renormalization-group calculatio n. The velocity-velocity correlation above and below the transition is described in terms of ''avalanches'' between different configurations . A companion paper examines the unusual finite-size effects evident i n the sliding state.