DRIVEN DIFFUSIVE SYSTEM WITH QUENCHED IMPURITIES

We study the effect of quenched impurities in a driven diffusive latti ce ps by means of numerical Monte Carlo simulations. The particles are driven by an external field. As the temperature is varied the system is found to undergo a second-order kinetic phase transition to an orde red strip-geometry state. In the ferromagnetic case an anisotropic fin ite-size-scaling analysis shows that the critical temperature decrease s linearly with increasing impurity concentration. We determine the po wer spectrum of the current correlations at the determined critical te mperatures and we also determine the conductivity as a function of the impurity concentration. In the antiferromagnetic case it follows from simulations and a finite-size-scaling analysis that the critical temp erature is a decreasing function of impurity concentration and that th e model is described by the Ising critical exponents.