Monte Carlo Study of Phase Transitions in the Bond-Diluted 3D 4-State Potts Model

TL;DR

This study uses large-scale Monte Carlo simulations to explore phase transitions in the bond-diluted 3D 4-state Potts model, identifying a tricritical point and analyzing the nature of phase transitions under disorder.

Contribution

It provides the first detailed analysis of the phase diagram and critical behavior of the bond-diluted 3D 4-state Potts model, including the identification of a tricritical point.

Findings

Existence of a tricritical point dividing first-order and continuous transition regimes.

Clarification of the nature of transitions via energy probability distribution analysis.

Estimation of critical exponents in the continuous transition regime.

Abstract

Large-scale Monte Carlo simulations of the bond-diluted three-dimensional 4-state Potts model are performed. The phase diagram and the physical properties at the phase transitions are studied using finite-size scaling techniques. Evidences are given for the existence of a tricritical point dividing the phase diagram into a regime where the transitions remain of first order and a second regime where the transitions are softened to continuous ones by the influence of disorder. In the former regime, the nature of the transition is essentially clarified through an analysis of the energy probability distribution. In the latter regime critical exponents are estimated. Rare and typical events are identified and their role is qualitatively discussed in both regimes.