Characterizing high-dimensional quantum contextuality

TL;DR

This paper develops systematic methods to verify and quantify quantum contextuality in fixed-dimensional systems, advancing understanding of its structure and resource potential in quantum information science.

Contribution

It introduces reliable techniques for checking if probability distributions originate from a specific quantum dimension and for measuring violations of noncontextuality inequalities.

Findings

Methods for verifying $d$-dimensional quantum contextuality

Revealed the non-convex structure of finite-dimensional contextuality

Provided tools for quantifying contextuality violations

Abstract

As a phenomenon encompassing measurement incompatibility and Bell nonlocality, quantum contextuality is not only central to our understanding of quantum mechanics, but also an essential resource in many quantum information processing tasks. The dimension-dependent feature of quantum contextuality is known ever since its discovery, but systematic methods for characterizing the quantum contextuality in systems with fixed dimension are still lacking. In this work, we solve this problem. We provide systematic and reliable methods for verifying whether or not an obtained probability distribution can result from a $d$-dimensional quantum system, as well as calculating finite-dimensional violation of a general noncontextuality inequality. As an application, our methods reveal the non-convex structure of finite-dimensional quantum contextuality.