Connecting microscopic simulations with kinetically constrained models of glasses

Area of Science:

• Physics
• Condensed Matter Physics
• Computational Physics

Background:

• Kinetically constrained spin models exhibit dynamics similar to glass-forming systems.
• These models are often viewed as coarse-grained representations of glass formers, characterized by a "mobility" field.
• The microscopic origin of this "mobility" field has been unclear due to a lack of coarse-graining methods.

Purpose of the Study:

• To establish a connection between microscopic glass dynamics and kinetically constrained spin models.
• To provide a coarse-graining procedure for deriving spin models from glass formers.
• To elucidate the nature of the "mobility" field in kinetically constrained spin models.

Main Methods:

• Developing a scheme to map the dynamics of a two-dimensional soft disk system.
• Translating the observed dynamics onto a kinetically constrained spin model framework.
• Analyzing the mapping to identify the corresponding "mobility" field.

Main Results:

• Successfully mapped the dynamics of a 2D soft disk glass former to a kinetically constrained spin model.
• Demonstrated a method for coarse-graining glass dynamics into spin model behavior.
• Provided insights into the microscopic underpinnings of the "mobility" field.

Conclusions:

• The study bridges the gap between microscopic glass dynamics and coarse-grained kinetically constrained spin models.
• A concrete method for deriving spin models from physical glass formers has been presented.
• This work offers a path towards a deeper understanding of glassy dynamics through spin model analogies.