2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90671It is argued that the appropriate framework to describe a microsystem as a correlation carrier between a source and a detector is non-equilibrium statistical mechanics for the compound source-detector system. An attempt is given to elucidate how this idealized notion of microsystem might arise inside a field theoretical description of isolated macrosystems: then decoherence appears as the natural limit of this idealization.9 pages, latex, no figures, Proceedings of the Fifth International Conference on Quantum Communication & Measurement, 2000 (Capri, Italy)Quantum Physicstext