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Discontinuous phase transition in a dimer lattice gas
1Departamento de Física and National Institute of Science and Technology for Complex Systems, ICEx, Universidade Federal de Minas Gerais, C. P. 702, Belo Horizonte, Minas Gerais 30123-970, Brazil. dickman@fisica.ufmg.br
The Journal of Chemical Physics
|May 16, 2012
Summary
Simulations reveal a discontinuous phase transition in a dimer model. This transition shows an 18% particle density jump and the emergence of orientational order, akin to the q=8 Potts model.
Area of Science:
- Statistical Mechanics
- Condensed Matter Physics
Background:
- Dimer models are crucial for understanding statistical mechanics and phase transitions.
- Nearest-neighbor exclusion defines interactions in many physical systems.
Purpose of the Study:
- To investigate the phase transition behavior of a dimer model with nearest-neighbor exclusion.
- To characterize the nature of the transition and associated ordering.
Main Methods:
- Tomographic entropic sampling for detailed simulations.
- Finite-size scaling and Binder's cumulant analysis.
- Comparison with the q=8 Potts model for theoretical understanding.
Main Results:
- A strongly discontinuous phase transition was observed.
- Particle density exhibits an 18% jump relative to its maximum value (1/4).
- The transition is associated with the onset of orientational order, forming a {1/2, 0, 1/2} structure.
Conclusions:
- The dimer model exhibits a discontinuous transition driven by chemical potential.
- The observed transition aligns with theoretical predictions for systems with eight equivalent maximum-density configurations.
- The model's behavior can be qualitatively understood through its connection to the q=8 Potts model.
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