Heterogeneous nucleation on complex networks with mobile impurities

TL;DR

This study investigates how impurity motion bias affects heterogeneous nucleation rates on complex networks, revealing a nonmonotonic relationship and the role of energy flux in facilitating nucleation.

Contribution

It introduces a non-equilibrium model with degree-biased impurity motion and analyzes its impact on nucleation, highlighting the nonmonotonic dependence of nucleation rate on motion bias.

Findings

Nucleation rate peaks at unbiased impurity motion ()

Impurity motion bias influences cluster features during nucleation

Energy flux induced by impurity diffusion facilitates barrier crossing

Abstract

We study the heterogeneous nucleation of Ising model on complex networks under a non-equilibrium situation where the impurities perform degree-biased motion controlled by a parameter \alpha. Through the forward flux sampling and detailed analysis on the nucleating clusters, we find that the nucleation rate shows a nonmonotonic dependence on \alpha for small number of impurities, in which a maximal nucleation rate occurs at \alpha=0 corresponding to the degree-uncorrelated random motion. Furthermore, we demonstrate the distinct features of the nucleating clusters along the pathway for different preference of impurities motion, which may be used to understand the resonance-like dependence of nucleation rate on the motion bias of impurities. Our theoretical analysis shows that the nonequilibrium diffusion of impurities can always induce a positive energy flux that can facilitate the barrier-crossing nucleation process. The nonmonotonic feature of the average value of the energy flux with \alpha may be the origin of our simulation results.