Finding the precise correspondence between lattice operators and the continuum fields that describe their long-distance properties is a largely open problem for strongly interacting critical points. Here we solve this problem essentially completely in the case of the three-state Potts model, which exhibits a phase transition described by a strongly interacting 'parafermion' conformal field theory. Using symmetry arguments, insights from integrability, and extensive simulations, we construct lattice analogues of nearly all the relevant and marginal physical fields governing this transition. This construction includes chiral fields such as the parafermion. Along the way we also clarify the structure of operator product expansions between order and disorder fields, which we confirm numerically. Our results both suggest a systematic methodology for attacking non-free field theories on the lattice and find broader applications in the pursuit of exotic topologically ordered phases of matter.
Spin interfaces and crossing probabilities of spin clusters in parafermionic models
我们考虑二维$Z_N$自旋晶格模型中的分形曲线。这些是N态自旋模型,其经历由ZN顺费米子场论描述的连续铁磁-顺磁相变。本文的主要目的是研究Schramm-Loewner演化(SLE)与扩展共形代数的共形场论(ECFT)之间的对应关系。利用蒙特卡罗模拟,计算了N=3和N=4自旋模型在Fateev-Zamolodchikov点处不同自旋界面的分形维数,这两个模型分别对应于三态Potts模型和Ashkin-Teller模型.这些数值措施,改善和完成在以前的作品中提出的,被证明是一致的SLE/ECFT预测。然后我们考虑自旋团簇在矩形区域中的交叉几率。使用多重SLE方法,我们提供了ZN副费米理论的交叉概率公式。通过求解秩为3的Knhiznik-Zamolodchikov系统来计算进入交叉概率公式的仿费米共形块。在三态Potts模型中,当副费米块与Virasoro块重合时,我们重新推导了S. M. Flores等人发现的交叉公式,这与我们的措施完全一致。当N ≥ 4时,交叉概率满足三阶微分方程而不是二阶微分方程,我们的公式是新的。的理论预测相比,在N=4和一个公平的协议被发现采取蒙特卡罗措施。
Melting of three-sublattice order in triangular lattice Ising antiferromagnets: Power-law order, $Z_6$ parafermionic multicriticality, and weakly first order transitions
Boundary conformal spectrum and surface critical behaviors of the classical spin systems: a tensor network renormalization study
本文对二维开边界格点上几个经典自旋模型,对由Cardy导子[J. L. Cardy,Nucl.Phys.B324,581(1989)]。为了提取精确的共形数据,我们实现了张量网络重整化算法[G。Evenbly和G. Vidal,Phys. Rev. Lett. 115,180405(2015)]扩展以适用于具有开放边界的正方形晶格。我们成功地计算了晶格上的Ising、三临界Ising和三态Potts模型的边界共形谱,该谱与基本的边界共形共形场论(BCFTs)相一致,从而证实了这些晶格模型的表面临界行为的BCFT分析的有效性.
QED$_3$-inspired three-dimensional conformal lattice gauge theory without fine-tuning
基于QED $_3$中诱导的非定域规范作用量与大量的无质量二分量Dirac费米子味$N$耦合,我们构造了一个只有规范自由度的共形格点理论.这个晶格系统显示的签名的临界规范可观的,没有任何微调的耦合,可以研究没有蒙特卡洛临界慢下来。通过将无质量费米子源精确耦合到格点规范模型,我们证明了费米子双线性中的非平凡反常维数依赖于费米子的无量纲电荷。我们提出了一个证明的原则格计算的各种费米子双线性三点函数的威尔逊系数。最后,通过将模型中费米子的电荷$q$映射到无质量QED $_3$中的味$N$,我们指出了低狄拉克谱的普适性和$N=2$ QED $_3$自对偶性的证据.