Experimental generalized contextuality with single-photon qubits

• DOI: 10.1364/optica.4.000966
• Publication Date: 2017-08-08T14:25:16Z
• Authors: Xiang Zhan; Eric G. Cavalcanti; Jian Li; Zhihao Bian; Yongsheng Zhang; Howard M. Wiseman; Peng Xue
• Keywords: Kochen–Specker theorem

Contextuality is a phenomenon at the heart of quantum mechanical departure from classical behaviour, and has been recently identified as resource in computation. Experimental demonstration contextuality thus an important goal. The traditional form -- violation Kochen-Specker inequality requires system with least three levels, status assumption determinism used deriving those inequalities controversial. By considering `unsharp' observables, Liang, Spekkens Wiseman (LSW) derived for generalized noncontextual models that doesn't assume determinism, applies already to qubit. We experimentally implement LSW test using polarization states heralded single photon unsharp binary measurements. violate by more than 16 standard deviations, showing our results cannot be reproduced subset theory.