Scalable Bell inequalities for graph states of arbitrary prime local dimension and self-testing

TL;DR

This paper introduces a general method to construct Bell inequalities maximally violated by graph states of any prime local dimension, enabling device-independent quantum protocols and self-testing of complex multipartite states.

Contribution

The authors develop a universal construction of Bell inequalities tailored for graph states of arbitrary prime dimension, including analytical determination of their maximal violation.

Findings

Constructed Bell inequalities for prime-dimensional graph states.

Analytically determined maximal quantum violations.

Demonstrated self-testing of multi-qutrit graph states.

Abstract

Bell nonlocality -- the existence of quantum correlations that cannot be explained by classical means -- is certainly one of the most striking features of quantum mechanics. Its range of applications in device-independent protocols is constantly growing. Many relevant quantum features can be inferred from violations of Bell inequalities, including entanglement detection and quantification, and state certification applicable to systems of arbitrary number of particles. A complete characterisation of nonlocal correlations for many-body systems is, however, a computationally intractable problem. Even if one restricts the analysis to specific classes of states, no general method to tailor Bell inequalities to be violated by a given state is known. In this work we provide a general construction of Bell inequalities that are maximally violated by graph states of any prime local dimension. These form a broad class of multipartite quantum states that have many applications in quantum information, including quantum error correction. We analytically determine their maximal quantum violation, a number of high relevance for device-independent applications of Bell inequalities. Finally, we show that these inequalities can be used for self-testing of multi-qutrit graph states such as the well-known four-qutrit absolutely maximally entangled state AME(4,3).