Metabasin dynamics of supercooled polymer melt

• 来源期刊: 中国物理B（英文版）
• 关键词: metabasin dynamics distance matrix democratic movement dynamic heterogeneity
• 年，卷（期）: 2019,（12）
• 页码范围: 305-310
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab4e82

摘要

We employ molecular dynamic simulation to investigate metabasin dynamics for supercooled polymer melt.We find that,in a small system,the α-relaxation process is composed of a few crossing events that the monomers hops from one metabasin to another.Each crossing event is very rapid and involves a democratic movement of many particles,whereas such collective motion is not string-like.Evaluation on the contributions of metabasin exploration and democratic movement shows that the structural relaxation is mostly governed by the latter.Our calculated results show that the metabasin-metabasin transitions are not the main reason of spatially dynamical heterogeneity.It is different from the binary Lennard-Jones mixture model in which the metabasin-metabasin transitions are relevant for the spatially dynamical heterogeneity.