Information Causality Characterizes the Set of Quantum Correlations in the Simplest Bell Scenario

@misc{gachechiladze2026information,
  title = {{Information Causality Characterizes the Set of Quantum Correlations in the Simplest Bell Scenario}},
  author = {Mariami Gachechiladze and Nikolai Miklin},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.10508},
  eprint = {2609.10508},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.10508},
}

TY  - UNPB
TI  - Information Causality Characterizes the Set of Quantum Correlations in the Simplest Bell Scenario
AU  - Mariami Gachechiladze
AU  - Nikolai Miklin
PY  - 2026
DA  - 2026/09/09
PB  - arXiv
DO  - 10.48550/arxiv.2609.10508
UR  - https://arxiv.org/abs/2609.10508
AB  - Information causality (IC) was introduced as a physical principle constraining correlations in non-signaling theories. Whether it can recover the exact quantum correlation boundary, beyond Uffink's inequality, has remained an open question. Here, we combine its generalized formulation for correlated inputs with a new communication protocol to derive quantum Bell inequalities that exactly characterize the quantum correlations in the simplest bipartite Bell scenario, with two binary measurements. In particular, we derive the Tsirelson-Landau-Masanes criterion directly from IC. Thus, the generalized IC implies macroscopic locality, while we also present macroscopically local correlations that violate the generalized IC. This establishes that generalized IC is a strictly stronger principle in this scenario. Together with our earlier result that generalized IC implies a nontrivial communication complexity principle, these findings strengthen the role of information causality in explaining the limits of quantum nonlocality and provide a systematic route to deriving tighter bounds on the set of quantum correlations in more general Bell scenarios.
ER  -