arXiv:cond-mat/0412698 · Journal of the Physical Society of Japan
Nonlinear Integral Equations for Thermodynamics of the \(U_{q}(\widehat{sl(r+1)})\) Perk–Schultz Model
Zengo Tsuboi, Minoru Takahashi
Abstract
We propose a system of nonlinear integral equations (NLIE) which describes the thermodynamics of the U_{q}(\hat{sl(r+1)}) Perk-Schultz model. These NLIE correspond to a trigonometric analogue of our previous result (cond-mat/0212280), and contain only r unknown functions. In particular, they reduce to Takahashi's NLIE for the XXZ spin chain (cond-mat/0010486) if r=1. We also calculate the high temperature expansion of the free energy. In particular for r=1 case, we have succeeded to derive the coefficients of order O((\frac{J}{T})^{99}).