- Letter
Theory-independent context incompatibility: Quantification and experimental demonstration
Phys. Rev. A 113, L010202 – Published 7 January, 2026
DOI: https://doi.org/10.1103/r2lr-72l7
Abstract
The concept of compatibility originally emerged as a synonym for the commutativity of observables and later evolved into the notion of measurement compatibility. In any case, however, it has remained predominantly algebraic in nature, tied to the formalism of quantum mechanics. Recently, still within the quantum domain, the concept of context incompatibility has been proposed as a resource for detecting eavesdropping in quantum communication channels. Here, we propose a significant generalization of this concept by introducing the notion of theory-independent context compatibility, a concept that is trivially satisfied by classical statistical mechanics but is found in conflict with quantum mechanics. Moreover, we propose a figure of merit capable of quantifying the degree of violation of theory-independent context incompatibility, and we experimentally demonstrate, using a quantum optics platform, that quantum systems can exhibit pronounced degrees of violation. Besides yielding a concept that extends to generic probabilistic theories and retrieving the notion of measurement incompatibility in the quantum domain, our results offer a promising perspective on evaluating the role of incompatibility in the manifestation of nonlocal correlations.
Physics Subject Headings (PhySH)
Corrections
21 January, 2026
Correction: The Supplemental Material was missing at publication and has been added. The citation for the Supplemental Material was inserted as Ref. [30] and subsequent references renumbered. A reference to Appendix B below Eq. (12) was changed to refer to the Supplemental Material.
