Journal of the Physical Society of Japan
Correlation Length for the XXZ Spin Chain at Finite Temperature
Hideyuki Mizuta, Taro Nagao, Miki Wadati
Abstract
Baxter's formula is extended to treat the thermodynamic properties of quantum spin chains. As an application of such formulation which we call finite temperature Baxter's formula, the XXZ Heisenberg spin chain is investigated. Combination of the formula and the finite size expansion provides a systematic method to evaluate low-temperature expansions of the thermodynamic quantities. The correlation length for the XXX spin chain is explicitly evaluated.