Combining recent advances in superconducting quantum hardware, we explore quantum correlations in a previously inaccessible regime by observing \emph{simultaneously} high-dimensional and many-body Bell non-locality. We report a high-confidence Bell violation in the correlations between two $d=64$ -dimensional systems encoded in twelve qubits. For system sizes up to $d=32$ , the strength of the observed nonlocal correlations exceeds the quantum upper bound for $d=2$ systems, providing direct evidence of high-dimensional nonlocality. Furthermore, we demonstrate that the observed violation is genuinely collective: all qubits contribute to the nonlocal correlations, while most pairwise correlations across the bipartition remain Bell-local. Our work illustrates how present-day quantum processors enable the exploration of fundamental predictions of quantum mechanics in previously inaccessible regimes and, in turn, how fundamental quantum effects can be used to benchmark their performance.Combining recent advances in superconducting quantum hardware, we explore quantum correlations in a previously inaccessible regime by observing \emph{simultaneously} high-dimensional and many-body Bell non-locality. We report a high-confidence Bell violation in the correlations between two $d=64$-dimensional systems encoded in twelve qubits. For system sizes up to $d=32$, the strength of the observed nonlocal correlations exceeds the quantum upper bound for $d=2$ systems, providing direct evidence of high-dimensional nonlocality. Furthermore, we demonstrate that the observed violation is genuinely collective: all qubits contribute to the nonlocal correlations, while most pairwise correlations across the bipartition remain Bell-local. Our work illustrates how present-day quantum processors enable the exploration of fundamental predictions of quantum mechanics in previously inaccessible regimes and, in turn, how fundamental quantum effects can be used to benchmark their performance.

quant-pharXiv:2604.24740Apr 28, 20260 citations

Characterization of Nonlocality in Chained Quantum Networks

Ya-Qi Dong, Yuqian Zhou, Qian-Kun Yao

Quantum information processing shows its superiority and particularity over classical information processing. One of the main characteristics that distinguishes quantum network from classical network is its nonlocality. The characterization and quantification of quantum nonlocality is the core task of quantum information and has great significance. In this paper, we study the nonlocality of a chain quantum network with three sources and four participants, construct a 3-local Bell inequality, and prove its quantum violation. Our results will promote the construction efficiency of Bell inequalities and contribute theoretical significance for quantum non-locality.Quantum information processing shows its superiority and particularity over classical information processing. One of the main characteristics that distinguishes quantum network from classical network is its nonlocality. The characterization and quantification of quantum nonlocality is the core task of quantum information and has great significance. In this paper, we study the nonlocality of a chain quantum network with three sources and four participants, construct a 3-local Bell inequality, and prove its quantum violation. Our results will promote the construction efficiency of Bell inequalities and contribute theoretical significance for quantum non-locality.

IEEE International Conference on Software Quality, Reliability and Security Companion (QRS-C)Dec 1, 20221 citation

Locality, Bell's theorem, and quantum mechanics

Peter Rastall

Foundations of PhysicsSep 1, 1985113 citations

Two‐Magnon Non‐Locality and Coherence Induced by an Open Microwave Cavity: Generation and Robustness

A.‐B. A. Mohamed, Hichem Eleuch

Abstract The generation and robustness of two‐magnon non‐locality and coherence dynamics induced by an open microwave field cavity are investigated in this work. The studied system consists of a two‐sublattice ferrimagnet coupled to a microwave field within an open cavity through its magnetic field component. The robustness of the two‐magnons non‐locality dynamics is analyzed using various non‐locality and coherence measures (namely, uncertainty‐induced non‐locality [UIN], maximal Bell function, and log‐negativity entanglement [L‐NE]) in the presence of the spontaneous emission and the electromagnetic‐wave dissipation. It is shown that photon‐magnon couplings, two‐magnon couplings, and dissipation all have an impact on the dynamical aspect of two‐magnon non‐locality and coherence. This work reveals that the two‐magnon non‐locality and coherence can be generated. For an initial maximal correlated two‐magnon state, the initial UIN non‐locality is shown to be more resilient than the maximum Bell function and log‐negativity. The amplitudes of the two‐magnon non‐locality quantifiers decline as a result of the two‐magnon coupling. The Bell non‐locality and L‐NE are reduced via spontaneous emission and dissipation, but the two‐magnon UIN‐coherence is preserved. These findings contribute to a better understanding of such dynamics and may shed light on measurement estimation in open quantum systems.Abstract The generation and robustness of two‐magnon non‐locality and coherence dynamics induced by an open microwave field cavity are investigated in this work. The studied system consists of a two‐sublattice ferrimagnet coupled to a microwave field within an open cavity through its magnetic field component. The robustness of the two‐magnons non‐locality dynamics is analyzed using various non‐locality and coherence measures (namely, uncertainty‐induced non‐locality [UIN], maximal Bell function, and log‐negativity entanglement [L‐NE]) in the presence of the spontaneous emission and the electromagnetic‐wave dissipation. It is shown that photon‐magnon couplings, two‐magnon couplings, and dissipation all have an impact on the dynamical aspect of two‐magnon non‐locality and coherence. This work reveals that the two‐magnon non‐locality and coherence can be generated. For an initial maximal correlated two‐magnon state, the initial UIN non‐locality is shown to be more resilient than the maximum Bell function and log‐negativity. The amplitudes of the two‐magnon non‐locality quantifiers decline as a result of the two‐magnon coupling. The Bell non‐locality and L‐NE are reduced via spontaneous emission and dissipation, but the two‐magnon UIN‐coherence is preserved. These findings contribute to a better understanding of such dynamics and may shed light on measurement estimation in open quantum systems.

Annalen der PhysikSep 7, 20220 citations

Making Sense of Bell’s Theorem and Quantum Nonlocality

S. P. Boughn

arXiv:1703.11003Foundations of PhysicsMar 27, 201758 citations

d=64

-dimensional systems encoded in twelve qubits. For system sizes up to

d=32

, the strength of the observed nonlocal correlations exceeds the quantum upper bound for

d=2

systems, providing direct evidence of high-dimensional nonlocality. Furthermore, we demonstrate that the observed violation is genuinely collective: all qubits contribute to the nonlocal correlations, while most pairwise correlations across the bipartition remain Bell-local. Our work illustrates how present-day quantum processors enable the exploration of fundamental predictions of quantum mechanics in previously inaccessible regimes and, in turn, how fundamental quantum effects can be used to benchmark their performance.