We investigate the violation of noncontextuality by a class of continuous-variable states, including variations of entangled coherent states and a two-mode continuous superposition of coherent states. We generalize the Kochen-Specker (KS) inequality discussed by Cabello [A. Cabello, Phys. Rev. Lett. 101, 210401 (2008)] by using effective bidimensional observables implemented through physical operations acting on continuous-variable states, in a way similar to an approach to the falsification of Bell-Clauser-Horne-Shimony-Holt inequalities put forward recently. We test for state-independent violation of KS inequalities under variable degrees of state entanglement and mixedness. We then demonstrate theoretically the violation of a KS inequality for any two-mode state by using pseudospin observables and a generalized quasiprobability function.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
McKeown, G., Paris, M. G. A., & Paternostro, M. (2011). Testing quantum contextuality of continuous-variable states. Physical Review A, 83(6), 062105. . https://doi.org/10.1103/PhysRevA.83.062105