Discrimination of measurement contexts in quantum mechanics

TL;DR

This paper shows how to identify different measurement contexts in quantum mechanics for certain observables, revealing that measurement routes can be distinguished even when predetermined values cannot.

Contribution

It introduces a method to discriminate measurement contexts in quantum systems where traditional hidden variable models fail.

Findings

Different measurement routes can be distinguished in quantum systems.

Discrimination is possible even when observables commute but are measured via different product routes.

The method highlights contextuality in quantum measurements.

Abstract

We demonstrate that it is possible to discern the way that has been followed to measure a quantum observable that can be expressed in terms of different products of observables, whereas no such discrimination is possible by assigning predetermined values. Specifically we show how to distinguish different routes (contexts) to measure C=AB=A'B', when C,A,B and C,A',B' commute with each other, but A and B do not commute with A' and B'.