2007/10/31 by Robert W. Spekkens · 6 citations
Arts and Humanities · Computer Science · Mathematics · Physics and Astronomy · Psychology · #Cognitive psychology #Computer science #Impossibility #Kochen–Specker theorem #Mathematics #Negativity effect #Philosophy and History of Science #Physics #Psychology #Pure mathematics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Representation (politics) #Statistical physics #Task (project management) #Theoretical physics #quant-ph
paper · pdf · doi:10.1103/physrevlett.101.020401
published as Phys. Rev. Lett. 101, 020401 (2008) · 5 pages, published version (modulo some supplementary material)
arxiv created 2008/06/30 · openalex publication_date 2008/07/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Two notions of nonclassicality that have been investigated intensively are: (i) negativity, that is, the need to posit negative values when representing quantum states by quasiprobability distributions such as the Wigner representation, and (ii) contextuality, that is, the impossibility of a noncontextual hidden variable model of quantum theory. Although both of these notions were meant to characterize the conditions under which a classical explanation cannot be provided, we demonstrate that they prove inadequate to the task and we argue for a particular way of generalizing and revising them. With the refined version of each in hand, it becomes apparent that they are in fact one and the same. We also demonstrate the impossibility of noncontextuality or non-negativity in quantum theory with a novel proof that is symmetric in its treatment of measurements and preparations.