Equivalence condition for the canonical and microcanonical ensembles in coupled spin systems
Statistical Mechanics
2010-11-09 v1 Quantum Physics
Abstract
It is typically assumed, without justification, that a weak coupling between a system and a bath is a necessary condition for the equivalence of a canonical ensemble and a microcanonical ensemble. For instance, in a canonical ensemble, temperature emerges if the system and the bath are uncoupled or weakly coupled. We investigate the validity region of this weak coupling approximation, using a coupled composite-spin system. Our results show that the spin coupling strength can be as large as the level spacing of the system, indicating that the weak coupling approximation has a much wider region of validity than usually expected.
Keywords
Cite
@article{arxiv.1007.3877,
title = {Equivalence condition for the canonical and microcanonical ensembles in coupled spin systems},
author = {Wenxian Zhang and C. P. Sun and Franco Nori},
journal= {arXiv preprint arXiv:1007.3877},
year = {2010}
}
Comments
5 pages, 5 figures, 4 tables, in RevTex 4.1 format