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Super-Arrhenius dynamic slowdown revealed by slow variable modulation in the fragile supercooled liquid
Zhiye Tang1,2, Shubham Kumar1, Shinji Saito1,2
1Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan.
The Journal of Chemical Physics
|April 8, 2026
Summary
Researchers explored particle jump dynamics in supercooled liquids to understand dynamic slowdown. They found that surrounding particle motion modulates jump rates, intensifying slowdown as temperature decreases, revealing a microscopic mechanism.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Statistical Mechanics
Background:
- Supercooled liquids exhibit a dynamic slowdown, a phenomenon not fully explained by current theories.
- Fragile glass-forming liquids show a super-Arrhenius dynamic slowdown, posing a significant challenge in condensed matter physics.
Purpose of the Study:
- To investigate the microscopic origins of the super-Arrhenius dynamic slowdown in fragile supercooled liquids.
- To analyze particle jump dynamics and identify key factors influencing dynamic slowdown in the Kob-Andersen Lennard-Jones (KALJ) model.
Main Methods:
- Analysis of particle jump dynamics using the displacement of jumping particles as a reaction coordinate.
- Comparison of survival probability with its slow-fluctuation limit, employing distribution shifts as slow variables.
- Investigating the spatial extent of slow variables and their correlation with static correlation length.
Main Results:
- Non-Poissonian dynamics emerge as temperature decreases in the Kob-Andersen Lennard-Jones (KALJ) model.
- Particles in the first coordination shell modulate jump dynamics and enhance jump rate fluctuations, inducing slowdown.
- The influence of slow variables spatially expands to outer coordination shells with decreasing temperature, intensifying the slowdown.
Conclusions:
- A microscopic mechanism for super-Arrhenius dynamic slowdown in fragile glass-forming liquids is identified.
- The spatial growth of dynamic disorder, correlated with static correlation length, drives the dynamic slowdown.
- Understanding these dynamics is crucial for predicting the behavior of supercooled liquids and glasses.
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