1999/07/05 by Karl Svozil, Svozil, Karl
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/9907015
openalex publication_date 1999/07/05 · arxiv created 1999/08/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Two entangled particles in threedimensional Hilbert space (per particle) are considered in an EPR-type arrangement. On each side the Kochen-Specker observables \J12,J22,J32\ and \ J12, J22,J32\ with [J12, J12]≠ 0 are measured. The outcomes of measurements of J32 (via J12,J22) and J32 (via J12, J22) are compared. Although formally J32 is associated with the same projection operator, a strong form of quantum contextuality states that an outcome depends on the complete disposition of the measurement apparatus, in particular whether J12 or J12 is measured alongside. It is argued that in this case it is impossible to measure contextuality directly, a necessary condition being a non-operational counterfactuality of the argument.