Nonequilibrium characterization of spinodal points using short time dynamics.

Area of Science:

• Thermodynamics and statistical mechanics
• Phase transitions
• Condensed matter physics

Background:

• The spinodal concept is rigorously defined only for infinite-range (mean-field) systems.
• In short-range systems, the true spinodal is unreachable, with only a pseudospinodal obtainable via extrapolation.
• Existing methods for short-range systems are limited by metastability and equilibration challenges.

Purpose of the Study:

• To establish a practical and sensible definition for spinodal points in short-range systems.
• To connect the concept of spinodal behavior to observable dynamical properties.
• To provide a method for determining spinodal points that bypasses equilibration issues.

Main Methods:

• Analyzing the short-time dynamical behavior of systems within the metastable phase.
• Identifying a critical point in the system's dynamics.
• Comparing dynamically determined spinodal points with established theoretical definitions.

Main Results:

• A new definition of spinodal points is proposed based on critical dynamical behavior.
• Dynamically determined spinodal points in short-range systems match thermodynamical spinodal points in mean-field systems.
• The proposed method yields results consistent with pseudospinodal points obtained by extrapolation in short-range systems.

Conclusions:

• Short-time critical dynamics offer a viable route to define and determine spinodal points in short-range systems.
• This dynamical approach provides a practical alternative to equilibrium-based methods, overcoming metastability limitations.
• The findings bridge the gap between theoretical spinodal concepts and experimental determination in diverse systems.