On the order of the phase transition in the spin-1 Baxter-Wu model

TL;DR

This study investigates the ambiguous nature of the phase transition in the spin-1 Baxter-Wu model, revealing potential multicritical behavior with coexistence of different magnetic phases.

Contribution

It provides the first extensive entropic simulation analysis of the spin-1 Baxter-Wu model's phase transition, highlighting its indeterminate order and possible multicriticality.

Findings

Results are inconclusive for the transition's order, showing features of both continuous and discontinuous transitions.

Evidence suggests the presence of a tetracritical point with coexisting magnetic phases.

The model may belong to a critical line with multicritical behavior involving external or crystalline fields.

Abstract

In this work we investigate the order of the phase transition of the spin-1 Baxter-Wu model. We used extensive entropic simulations to describe the behavior of quantities which reveal the order of the phase transition. We applyied finite-sizing scaling laws for continuous and discontinuous phase transitions. Our results show that this system exhibits an indeterminacy regarding the order of the phase transition, i.e., the results are conclusive for both transitions, whether continuous or discontinuous. In such a scenario we carried out a study of the configurations in the region of the phase transition, which confirmed that the model seems to undergo a tetracritical transition, with the coexistence of a ferromagnetic and three ferrimagnetic configurations, suggesting that it may be a multicritical point belonging to a critical line of an external or a crystalline fields, where the continuous and the discontinuous phase transitions may coexist reflecting different features of the system