Monte Carlo Simulations of the Blinking-Checkers Model for Polyamorphic Fluids

TL;DR

This paper uses Monte Carlo simulations to study the blinking-checkers model, revealing polyamorphic phase behavior and critical phenomena consistent with the 3D Ising universality class, differing from mean-field predictions.

Contribution

First simulation-based analysis of the blinking-checkers model showing phase behavior and critical points influenced by fluctuations, confirming its universality class.

Findings

Polyamorphic phase behavior confirmed by simulations

Critical points differ from mean-field predictions

Model belongs to 3D Ising universality class

Abstract

The blinking-checkers model [F. Caupin and M. A. Anisimov, Phys. Rev. Lett, 127,185701 (2021)] is a minimal lattice model which has demonstrated that, in the meanfield approximation, it can reproduce the phenomenon of fluid polyamorphism. This model is a binary lattice-gas, in which each site has three possible states: empty, occupied with particles of type 1, and occupied with particles of type 2. Additionally, the two types of particles may interconvert from one to another. Equilibrium interconversion imposes a constraint that makes this model thermodynamically equivalent to a single-component system. In this work, Monte-Carlo simulations of the blinking-checkers model are performed, demonstrating polyamorphic phase behavior. The locations of the liquid-liquid and liquid-gas critical points are found to be different from the meanfield predictions for this model with the same interaction parameters, as the phase behavior is significantly affected by critical fluctuations. Based on the computed values of the critical exponents of the order parameter, susceptibility, correlation length, and surface tension, we confirm that the blinking-checkers model, for both liquid-gas and liquid-liquid equilibria, belongs to the three-dimensional Ising class of critical-point universality.