An Overview on Short and Long Time Relaxations in Glass-forming Supercooled Liquids

27th IUPAP Conference on Computational Physics

物理学;计算机科学

Karmakar, Smarajit^1

Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 21 Brundavan Colony, Narsingi, Hyderabad

500075, India^1

关键词: Cooperative phenomenon;    Density fluctuation;    Finite-size scaling analysis;    Glass-forming liquid;    Long-time relaxations;    Molecular dynamics simulations;    Spatial heterogeneity;    Supercooled liquids;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/759/1/012008/pdf
DOI  :  10.1088/1742-6596/759/1/012008

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Density fluctuations in supercooled liquids near the glass transition relax in multiple steps. The short time relaxation is known as β-relaxation and the final long time relaxation is called α-relaxation. It is believed that the long time α-relaxation is a cooperative phenomena associated with a growing length scales, whereas the short-time β-relaxation is often attributed to spatially local processes involving the rattling motion of a particle in the transient cage formed by its neighbors. Using molecular dynamics simulations of few model glass-forming liquids, we show that the β-relaxation is also cooperative in nature and the length scale extracted from the detailed finite-size scaling analysis of β-relaxation is found to be the same as that of the length scale that describes the spatial heterogeneity of local dynamics in the long-time α-relaxation regime. These results provide a clear connection between short-time dynamics and long-time structural relaxation in glass-forming liquids.