Negativity and Contextuality are Equivalent Notions of Nonclassicality

摘要: Two notions of nonclassicality that have been investigated intensively are: (i) negativity, is, the need to posit negative values when representing quantum states by quasiprobability distributions such as Wigner representation, and (ii) contextuality, impossibility a noncontextual hidden variable model theory. Although both these were meant characterize conditions under which classical explanation cannot be provided, we demonstrate they prove inadequate task argue for particular way generalizing revising them. With refined version each in hand, it becomes apparent are fact one same. We also noncontextuality or non-negativity theory with novel proof is symmetric its treatment measurements preparations.