Generalized monogamy of contextual inequalities from the no-disturbance principle

TL;DR

This paper generalizes the concept of monogamy of Bell violations to the monogamy of contextuality in single systems using graph theory, linking it to no-disturbance and causality violations, with experimental testability.

Contribution

It introduces a graph-theoretic framework to establish monogamy relations for contextual inequalities in quantum systems, extending prior Bell inequality monogamy results.

Findings

Monogamy of contextual inequalities can be derived from graph decompositions.

Chordal graphs admit joint probability distributions, enabling monogamy relations.

Quantum systems can violate these monogamy relations, indicating causality issues.

Abstract

In this paper we demonstrate that the property of monogamy of Bell violations seen for no-signaling correlations in composite systems can be generalized to the monogamy of contextuality in single systems obeying the Gleason property of no-disturbance. We show how one can construct monogamies for contextual inequalities by using the graph-theoretic technique of vertex decomposition of a graph representing a set of measurements into subgraphs of suitable independence numbers that themselves admit a joint probability distribution. After establishing that all the subgraphs that are chordal graphs admit a joint probability distribution, we formulate a precise graph-theoretic condition that gives rise to the monogamy of contextuality. We also show how such monogamies arise within quantum theory for a single four-dimensional system and interpret violation of these relations in terms of a violation of causality. These monogamies can be tested with current experimental techniques.