Dynamics of Phase Transitions with Fluctuations

Abstract

In spatially extended systems undergoing nonequilibrium phase transitions, it is interesting to analyze not only the location and universality of critical points (which was studied in Chapter 3), but also the dynamical evolution of the system toward its steady state. In some physical processes, such as phase separation in binary mixtures or alloys, the dynamics of the system is in fact a very relevant problem, in which many research efforts have been invested in the last decades (for a classical review, see [GSS83]). This chapter is devoted to study the effect of spatiotemporal noise on this kind of phenomena. First we discuss the role of thermal noise in a general model of phase separation (Section 4.1), for which internal noise has a multiplicative nature. Then we examine the effect of external (also multiplicative) noise in a standard conserved model (Section 4.2). In that case, we will see that external noise can induce phase separation.