Delocalization-Induced Interface Broadening in Strongly Interacting Systems

Abstract

In this chapter we illuminate unexpected effects of correlations on the structure and thermodynamics of interfaces and in turn phase separation, which are decisive in systems with strong interactions. More specifically, in Chap. 3 we encountered an unexpected effect of the BG concentration profile, which we named interface broadening. Based on the derived Cahn-Hilliard field theory, we found that the one-dimensional equilibrium concentration profile broadens upon increasing the coupling strength above and near the thermal energy (see Fig. 3.2 ). Thus far we have not explained what the underlying physical mechanism behind interface broadening is. In this chapter we show that interface broadening is the result of an entropy-driven interface delocalization transition, which is not accounted for in the widely adopted MF theory. Pair correlations enforce a thermodynamically optimal configuration of defects, and profoundly affect nucleation and spinodal decomposition at strong coupling. Part of this chapter has been published in Physical Review Research under the terms of the Creative Commons Attribution 4.0 International license [1]