Bell tests show that quantum correlations cannot be explained by any local classical theory. Yousef Mafi, Ali Moghaddam and Teemu Ojanen of QMAT's Theory of Quantum Matter group at Tampere University have used a superconducting quantum processor to observe non-locality that is simultaneously high-dimensional and many-body.

They report a high-confidence Bell violation between two 64-dimensional systems encoded in twelve qubits. For systems up to 32 dimensions, the correlations exceed the quantum bound for two-dimensional systems, direct evidence of high-dimensional non-locality. The violation is genuinely collective: all qubits contribute, while most pairwise correlations across the divide remain Bell-local. The authors note that such tests both probe fundamental quantum predictions and benchmark today's quantum processors.

The preprint has not yet been peer reviewed.

Figure: Mafi et al., arXiv:2604.24740 (2026)