| Abrupt, discontinuous changes (known as 'avalanches') are ubiquitous in the dynamics of driven, disordered systems. This ubiquity hints at the possibility of a simple, unified understanding of this behavior in the otherwise complex, difficult systems that exhibit it. This work studies two related model systems (the random-bond Ising model and the random-field Ising model) that demonstrate avalanche phenomena, in order to quantify the commonality of such phenomena in these systems. The results indicate quite clearly that such studies of these two models are indeed universal, in the same sense that the critical phase transition behavior of thermodynamic systems is universal. The phase diagram of these two models is also determined. In addition, the results also show indications of anomalous diffusion behavior at play behind the observed avalanche behavior. The implications of all these results for the study of driven disordered systems are discussed. |
