Rob Spekkens & Matthew Pusey
- Perimeter Institute
1) How to experimentally test the notion of noncontextuality
Rob Spekkens
2) How to demonstrate contextuality in a realistic experiment
Matthew Pusey
Contextuality is the leading notion of non-classicality for a single system. However, the current standard approach to "contextuality inequalities" invokes an assumption of outcome determinism, unjustified in a noisy experiment. More careful proposals do not make this assumption, but still require operational equivalences between preparation procedures that will never obtain exactly in practice. Focussing here on the simplest non-trivial case, four preparations and two binary measurements, I exploit a subtle connection the CHSH scenario to obtain a complete characterisation of the non-contextual experimental statistics as eight non-linear inequalities. Violating such an inequality may come as close as is possible to a "loophole-free" refutation of non-contextuality.