Quantum mechanics is contextual, that is, the outcome of a measurement does depend on how that value is measured. This somewhat bizarre, non-classical feature is a consequence of the Kochen-Specker theorem, which asserts that there is no non-contextual hidden variable theory that reproduces quantum theory. Contextuality is a property of quantum systems with Hilbert spaces of d > 2, as it can be...

Models of a phenomenon are often developed by examining it under different experimental conditions, or measurement contexts. The resultant probabilistic models assume that the underlying random variables, which define a measurable set of outcomes, can be defined independent of the measurement context. The phenomenon is deemed contextual when this assumption fails. Contextuality is an important ...

Two fundamental quantum resources, nonlocality and contextuality, can be connected through Bell inequalities that are violated by state-independent contextuality (SI-C) sets. These allow for applications require simultaneous contextuality. However, existing inequalities, the produced SI-C sets is very sensitive to noise. This precludes experimental implementation. Here we identify which optimal...

We present a new quantum secret sharing protocol based on recent advances in Mermin-type contextuality scenarios, which is provably secure against postquantum nonsignaling attackers. It is a fundamental assumption of secret sharing protocols that not all players are trusted parties, and that some may collude amongst themselves and with eavesdroppers to break confidentiality. To this extent, qua...

Motivated by the importance of contextuality and a work on the robustness of the entanglement of mixed quantum states, the robustness of contextuality (RoC) RC(e) of an empirical model e against non-contextual noises was introduced and discussed in Science China Physics, Mechanics and Astronomy (59(4) and 59(9), 2016). Because noises are not always non-contextual, this paper introduces and disc...

The Contextuality-by-Default approach to determining and measuring the (non)contextuality of a system random variables requires that every variable in be represented by an equivalent set dichotomous variables. In this paper we present general principles justify use dichotomizations determine their choice. main idea choosing is if possible values endowed with pre-topology (V-space), then allowab...