Spontaneous Polarization of the z_n-Baxter Model : Bootstrap Approach to Integrable Lattice Models

抄録

In Part I bootstrap scheme for integrable model is presented; i.e., it is shown that correlation functions of vertex models satisfying the Yang-Baxter equation, the unitarity and the crossing symmetry, obey a system of difference equations. This scheme is useful to various models such as the six-vertex model, the eight-vertex model and so on. In Part II the Z_n-Baxter model, the higher rank version of the eight-vertex model, is studied as an example. In particular, the spontaneous polarization (one-point function) in the principal regime of this model is obtained by solving the simplest difference equation.