abstract: Entanglement between degrees of freedom, namely between the spin, path and (total) energy degrees of freedom, for single neutrons is exploited. We implemented a triply entangled Greenberger-Horne-Zeilinger(GHZ)-like state and coherently manipulated relative phases of two-level quantum subsystems. An inequality derived by Mermin was applied to analyze the generated GHZ-like state: we determined the four expectation values and finally obtained [Formula: see text]. This demonstrates the violation of a Mermin-like inequality for triply entangled GHZ-like state in a single-particle system, which, in turn, exhibits a clear inconsistency between noncontextual assumptions and quantum mechanics and confirms quantum contextuality.
authors.affiliation: Atominstitut, Technische Universität Wien, Stadionallee 2, A-1020 Wien, Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Durstberger-Rennhofer
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hasegawa