Evaluation of memory effects at phase transitions and during relaxation processes

Area of Science:

• Physics
• Physical Chemistry
• Statistical Mechanics

Background:

• Phase transitions are fundamental in many physical systems.
• Describing the dynamics of phase transitions, especially memory effects, is complex.
• Existing models often lack direct links to experimental observations.

Purpose of the Study:

• To develop a theoretical framework for phase transition dynamics.
• To connect microscopic memory effects to macroscopic, experimentally measurable quantities.
• To simplify the analysis of phase transition kinetics.

Main Methods:

• Utilizing a nonstationary generalized Langevin equation for the order parameter.
• Introducing a memory kernel to model nonlocal time effects.
• Relating the memory kernel's extent to experimental induction time and transition duration.
• Employing a simple kinematic model for theoretical analysis.
• Conducting computer simulations on various model systems (Potts model, dipole gas, anharmonic spring, nucleation).

Main Results:

• The extent of the memory kernel is positively correlated with the duration of the phase transition.
• The memory kernel's magnitude is of the same order as the transition duration.
• The distribution of induction times does not significantly affect the memory kernel.
• Computer simulations confirm the theoretical model's consistency across diverse systems.

Conclusions:

• The proposed Langevin equation provides a robust framework for phase transition dynamics.
• The study successfully links theoretical memory effects to observable experimental parameters.
• The findings offer a simplified yet accurate method for analyzing phase transition kinetics in various physical systems.