Using the properties of the local Boltzmann weights of integrable interaction-round-a-face (IRF or face) models we express local operators in terms of generalized transfer matrices. This allows for the derivation of discrete functional equations for the reduced density matrices in inhomogeneous generalizations of these models. We apply these equations to study the density matrices for IRF models of various solid-on-solid type and quantum chains of non-Abelian ${SU(2)_3}$ or Fibonacci anyons. Similar as in the six vertex model we find that reduced density matrices for a sequence of consecutive sites can be 'factorized', i.e.\ expressed in terms of nearest-neighbour correlators with coefficients which are independent of the model parameters. Explicit expressions are provided for correlation functions on up to three neighbouring sites.

中文翻译：

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可积人脸模型中的密度矩阵

使用可积分交互圆脸（IRF 或人脸）模型的局部 Boltzmann 权重的特性，我们根据广义转移矩阵来表达局部算子。这允许在这些模型的非齐次泛化中推导用于降低密度矩阵的离散函数方程。我们应用这些方程来研究各种固体对固体类型的 IRF 模型和非阿贝尔 ${SU(2)_3}$ 或斐波那契任意子的量子链的密度矩阵。与六顶点模型类似，我们发现一系列连续位点的减少密度矩阵可以被“分解”，即用具有独立于模型参数的系数的最近邻相关器表示。为最多三个相邻站点上的相关函数提供了显式表达式。