Bell test Bell’s theorem EPR steering Einstein–Podolsky–Rosen argument KS Box Non-contextuality inequality PR Box PR box Stern–Gerlach experiment Wigner-function simulations axioms for quantum theory biological quantum decoherence channel capacity channel entropy classical limit collapse of the quantum state communication complexity continuous-variable states controlled-NOT density-matrix formalism device-independent discrete-variable states entanglement entropic uncertainty relation general entropies hybrid entanglement hypothesis testing ion channels local hidden variables local polytope