Local vs. cooperative: Unraveling glass transition mechanisms with SEER

• 成果类型: Article
• 署名作者: Ciamarra, Massimo Pica; Ji, Wencheng; Wyart, Matthieu
• 署名单位: Nanyang Technological University; Consiglio Nazionale delle Ricerche (CNR); Weizmann Institute of Science; Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10019
• DOI: 10.1073/pnas.2400611121
• 发表日期: 2024-05-28
• 关键词: supercooled liquids; dynamical heterogeneities; configurational entropy; MODEL; relaxation; phase

摘要

Which phenomenon slows down the dynamics in supercooled liquids and turns them into glasses is a long-standing question of condensed matter. Most popular theories posit that as the temperature decreases, many events must occur in a coordinated fashion on a growing length scale for relaxation to occur. Instead, other approaches consider that local barriers associated with the elementary rearrangement of a few particles or excitations govern the dynamics. To resolve this conundrum, our central result is to introduce an algorithm, Systematic Excitation ExtRaction, which can systematically extract hundreds of excitations and their energy from any given configuration. We also provide a measurement of the activation energy, characterizing the liquid dynamics, based on fast quenching and reheating. We use these two methods in a popular liquid model of polydisperse particles. Such polydisperse models are known to capture the hallmarks of the glass transition and can be equilibrated efficiently up to millisecond time scales. The analysis reveals that cooperative effects do not control the fragility of such liquids: the change of energy of local barriers determines the change of activation energy. More generally, these methods can now be used to measure the degree of cooperativity of any liquid model.