Progress of Theoretical Physics
Statistical Mechanics of a Spin-Boson System: The Dynamic Compensation Theorem and the Exact Partition Function
T. Tsuzuki
Abstract
We first extend the dynamic compensation theorem of infrared divergence for the case of finite temperatures and then obtain the exact partition function of the spin-boson system, which is different from the previous ones. We find that there exists no thermodynamic equivalence between the spin-boson system and the Kondo system in general and that such equivalence is restricted to the case of high temperature limit.