Investigating amorphous order in stable glasses by random pinning

Area of Science:

• Condensed Matter Physics
• Materials Science
• Statistical Mechanics

Background:

• Glass-forming liquids exhibit complex dynamics near their glass transition.
• Equilibrium states of these systems are characterized by short-range correlations.
• Understanding the nature of stable glassy states is crucial for materials design.

Purpose of the Study:

• To investigate the structural properties of stable glassy states.
• To determine the nature of correlations within these non-equilibrium states.
• To explore the relationship between correlations and the stability of glassy states.

Main Methods:

• Biasing glass-forming liquids to reduced dynamical activity.
• Pinning the positions of a subset of particles.
• Analyzing many-body correlations in the pinned configurations.

Main Results:

• Stable glassy states show significantly stronger and longer-ranged many-body correlations than equilibrium states.
• These correlations persist even in apparently disordered configurations.
• The degree of correlation is linked to the stability of the glassy state.

Conclusions:

• Stable glassy states possess a form of "amorphous order" characterized by strong many-body correlations.
• This amorphous order provides a microscopic explanation for the enhanced stability of these non-equilibrium glassy states.
• The findings support a paradigm shift in understanding glassy systems beyond equilibrium thermodynamics.