Delve into the future of research at MiS with our preprint repository. Our scientists are making groundbreaking discoveries and sharing their latest findings before they are published. Explore repository to stay up-to-date on the newest developments and breakthroughs.
MiS Preprint
14/2007
Sharp-interface limit of a mesoscopic free energy with a random external field
Nicolas Dirr and Enza Orlandi
Abstract
We add a random bulk term, modeling the interaction with the impurities of the medium, to a standard functional in the gradient theory of phase transitions consisting of a gradient term with a double well potential. For the resulting functional we study the asymptotic properties of minimizers and minimal energy under a rescaling in space, i.e. on the macroscopic scale. By bounding the energy from below by a coarse-grained, discrete functional, we show that for a suitable strength of the random field the random energy functional has two types of random global minimizers, corresponding to two phases. Then we derive the macroscopic cost of low-energy "excited" states that correspond to a bubble of one phase surrounded by the opposite phase.