Reentrant disorder-disorder transitions in generalized multicomponent Widom-Rowlinson models

Area of Science:

• Statistical Mechanics
• Condensed Matter Physics
• Phase Transitions

Background:

• The Widom-Rowlinson (WR) model describes phase separation in multicomponent systems.
• Hard-core exclusion between unlike particles is a simplification.
• Realistic interactions are crucial for understanding complex phase behavior.

Purpose of the Study:

• To generalize the multicomponent WR model with finite repulsion.
• To investigate the impact of finite repulsion on phase transitions.
• To explore reentrant transitions and universality classes.

Main Methods:

• Exact solution on the Bethe lattice.
• Corner Transfer Matrix Renormalization Group (CTMRG) on a 2D square lattice.
• Analysis of phase diagrams for varying repulsion strengths and particle numbers (M).

Main Results:

• Finite repulsion transforms second-order gas-demixed transitions into first-order transitions.
• Weakening repulsion shrinks the crystal phase region.
• A reentrant transition via an ordered crystal phase is observed for specific repulsion strengths.
• The generalized model belongs to the Ising universality class.

Conclusions:

• Finite repulsion significantly alters the phase diagram of the multicomponent WR model.
• Reentrant transitions provide a mechanism for complex phase behavior.
• The Ising universality class governs the critical phenomena in this generalized model.