Heterogeneous nucleation on complex networks with mobile impurities

¹ Department of Physics, Anqing Normal University - Anqing, 246011, China
² School of Physics and Material Science, Anhui University - Hefei, 230039, China
³ Hefei National Laboratory for Physical Sciences at Microscales & Department of Chemical Physics, University of Science and Technology of China - Hefei, 230026, China

^(a) hzhlj@ustc.edu.cn

Received: 1 June 2015
Accepted: 10 August 2015

Abstract

We study the heterogeneous nucleation of Ising model on complex networks under a nonequilibrium situation where the impurities perform degree-biased motion controlled by a parameter α. Through the forward flux sampling and detailed analysis on the nucleating clusters, we find that the nucleation rate shows a nonmonotonic dependence on α for small number of impurities, in which a maximal nucleation rate occurs at 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 α may be the origin of our simulation results.