Point-to-set lengths, local structure, and glassiness

Area of Science:

• Materials Science
• Condensed Matter Physics
• Physical Chemistry

Background:

• Glass-forming liquids exhibit increasing sluggishness with rising structural order.
• The precise nature of this order (local vs. amorphous) is a subject of ongoing scientific debate.
• Previous measures like point-to-set (PTS) correlation lengths have shown limitations in generality.

Purpose of the Study:

• To extend the definition of point-to-set (PTS) correlations.
• To develop a method for agnostic capture of any growing order in liquids.
• To differentiate between critical ordering and glassiness in liquid dynamics.

Main Methods:

• Generalized the definition of point-to-set (PTS) correlations.
• Applied the extended PTS correlations to analyze structural order in liquids.
• Developed a framework to distinguish different types of liquid ordering.

Main Results:

• The generalized PTS correlations can capture both local and amorphous order.
• A clear distinction is established between slowing down due to critical ordering and glassiness.
• The study provides a unified approach to assess various forms of order in glass formation.

Conclusions:

• The extended PTS correlation framework offers a more general measure of amorphous order.
• This framework allows for a nuanced understanding of the origins of liquid sluggishness.
• It provides critical insights into the fundamental processes governing glass formation.