[Zhang, WX] Fudan Univ, Key Lab Micro & Nano Photon Struct, Dept Opt Sci & Engn, Shanghai 200433, Peoples R China; [Zhang, WX; Sun, CP; Nori, F] RIKEN, Adv Sci Inst, Wako, Saitama 3510198, Japan; [Sun, CP] Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China; [Nori, F] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA
英文摘要:
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.
Zhang, Wenxian,Sun, C. P.,Nori, Franco. Equivalence condition for the canonical and microcanonical ensembles in coupled spin systems[J]. PHYSICAL REVIEW E,2010,82(4):-.
