Correlation functions of integrable O(n) spin chains

Abstract

We study the correlation functions of the integrable O(n) spin chain in the thermodynamic limit. We addressed the problem of solving functional equations of the quantum Knizhnik Zamolodchikov type for density matrix related to the O(n) spin chain. We give the explicit solution for two-sites density matrix elements for the O(n) which are then evaluated for the n=3,4,…,8 cases at zero temperature.