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Tong Hua's Team Revealed Structure-Dynamics Correlations of Supercooled Liquid

July 28, 2020      Author: Tong Hua

Recently, Tong Hua’s team from School of Physics and Astronomy, SJTU published the latest findings about structure-dynamics correlations of supercooled liquid titled “Role of Attract Interactions in Structure Ordering and Dynamics of Glass-Forming Liquids” on Physical Review Letters, a world-famous journal in physics. This paper answers the classic problems that have been debated for more than 10 years in academia, points out the limitations of simple liquid theory, and provides insight into the development of supercooled liquid theory and the solution to glassy dynamics from the perspective of many-body structure order.

The first author of the paper is Associate Professor Tong Hua from School of Physics and Astronomy, and collaborating with him is Professor Hajime Tanaka from University of Tokyo.

Homepage of Tong Hua’s research team: https://www.physics.sjtu.edu.cn/huatong

Paper Link: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.225501

Abstract

A key question in glass physics is what the origin of slow glassy dynamics is. The liquid structure is a natural candidate; however, an apparently severe counterexample has been known. Two model glass-forming liquids, with the standard Lennard–Jones interaction potential and its Weeks–Chandler–Andersen variation without the attractive tail, exhibit very similar structures at the two-body level but drastically different dynamical behaviors in the supercooled states. Here we look at the liquid structure through a (many-body) structural order parameter Θ characterizing the packing capability of local particle arrangements. We show that the structures of these two systems seen by Θ are actually very different at a many-body level, but, quite surprisingly, the macroscopic structure (Θ)-dynamics (τα) relationships commonly follow a Vogel–Fulcher–Tammann-like function. Furthermore, the mutual information analysis reveals strong local structure-dynamics correlations. Therefore, we conclude that attractive interactions affect the liquid structure in a nonperturbative manner, but a general structural origin of slow dynamics holds for these systems.