Abstract Using a Monte Carlo simulation and the single histogram reweighting technique, we study the critical behaviors and phase transitions of the Baxter-Wu model on a two-layer triangular lattice with repulsive interlayer interactions. Via the finite-size analysis, we obtain the transition temperatures and critical exponents at different interlayer coupling strengths. The reduced energy cumulants and the histograms reveal pseudo-first-order phase transitions, and the critical exponents derivate from the standard Baxter-Wu model if the coupling is weak. As the increase of the coupling, the behavior of the pseudo-first order transition disappears and the critical exponents are in accordance with the ones known for the 2D 4-state Potts model.

中文翻译：

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具有排斥层间相互作用的双层自旋 1/2 Baxter-Wu 模型的相变

摘要 使用蒙特卡罗模拟和单直方图重加权技术，我们研究了 Baxter-Wu 模型在具有排斥层间相互作用的两层三角晶格上的临界行为和相变。通过有限尺寸分析，我们获得了不同层间耦合强度下的转变温度和临界指数。减少的能量累积量和直方图揭示了伪一阶相变，如果耦合较弱，则临界指数源自标准 Baxter-Wu 模型。随着耦合的增加，伪一阶跃迁的行为消失，临界指数与已知的二维 4 态 Potts 模型一致。