Using a Monte Carlo simulation and the single histogram reweighting technique, we study the critical behaviors and phase transitions of the Baxter–Wu (BW) model on a two-layer triangular lattice with Ising-type interlayer couplings. Via the finite-size analysis, we obtain the transition temperatures and critical exponents at repulsive and attractive interlayer couplings. The data for the repulsive interlayer coupling suggest continuous transitions, and the critical behaviors are the same as those of the 2D BW model, belonging to the four-state Potts universality class. The reduced energy cumulants and the histograms reveal that attractive coupling leads to weak first-order phase transitions. The pseudocritical exponents with the existence of the interlayer couplings indicate that the first-order transition is very close to the critical point of the 2D standard BW model.

使用蒙特卡罗模拟和单直方图重加权技术，我们研究了具有伊辛型层间耦合的两层三角形晶格上Baxter-Wu（BW）模型的临界行为和相变。通过有限尺寸分析，我们获得了排斥层和有吸引力的层间耦合处的转变温度和临界指数。排斥层间耦合的数据表明存在连续过渡，其临界行为与2D BW模型的临界行为相同，属于四态Potts通用性类别。降低的能量累积量和直方图显示，有吸引力的耦合导致弱的一阶相变。