Authors: Rodrigo Vargas
Publish Date: 2008/08/06
Volume: 133, Issue: 3, Pages: 491-511
Abstract
We establish the existence of two weak coupling regime effective dynamics for an open quantum system of repeated interactions vanishing strength and individual interaction duration respectively This generalizes known results Attal and Joye in J Stat Phys 1261241–1283 2007 in that the von Neumann algebras describing the system and the chain element may not be of finite type Then but now assuming that the small system is of finite type we prove that both effective dynamics capture the longterm behavior of the system existence of a unique asymptotic state for them implies the same property for the respective exact dynamics—provided that the perturbation parameter is sufficiently small The zeroth order term in a power series expansion in the perturbation parameter of such an asymptotic state is given by the asymptotic state of the effective dynamics We conclude by working out the case in which the small system and the chain element are spins
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