Orthocomplementation and compound systems
Boris Ischi
Abstract. In their 1936 founding paper on quantum logic, Birkhoff and von Neumann postulated that the lattice describing the experimental propositions concerning a quantum system is orthocomplemented. We prove that this postulate fails for the lattice Lsep describing a compound system consisting of so called separated quantum systems. By separated we mean two systems prepared in different “rooms ” of the lab, and before any interaction takes place. In that case the state of the compound system is necessarily a product state. As a consequence, Dirac’s superposition principle fails, and therefore Lsep cannot satisfy all Piron’s axioms. In previous works, assuming that Lsep is orthocomplemented, it was argued that Lsep is not orthomodular and fails to have the covering property. Here we prove that Lsep cannot admit and orthocomplementation. Moreover, we propose a natural model for Lsep which has the covering property. PACS numbers: 03.65.Ta, 03.65.Ca 1.
•Oct 12, 2004•4 citations