English

Exploring the boundary of quantum correlations with a time-domain optical processor

Quantum Physics 2025-01-31 v3 Optics

Abstract

Contextuality is a hallmark feature of the quantum theory that captures its incompatibility with any noncontextual hidden-variable model. The Greenberger--Horne--Zeilinger (GHZ)-type paradoxes are proofs of contextuality that reveal this incompatibility with deterministic logical arguments. However, the GHZ-type paradox whose events can be included in the fewest contexts and which brings the strongest nonclassicality remains elusive. Here, we derive a GHZ-type paradox with a context-cover number of three and show this number saturates the lower bound posed by quantum theory. We demonstrate the paradox with a time-domain fiber optical platform and recover the quantum prediction in a 37-dimensional setup based on high-speed modulation, convolution, and homodyne detection of time-multiplexed pulsed coherent light. By proposing and studying a strong form of contextuality in high-dimensional Hilbert space, our results pave the way for the exploration of exotic quantum correlations with time-multiplexed optical systems.

Keywords

Cite

@article{arxiv.2208.07794,
  title  = {Exploring the boundary of quantum correlations with a time-domain optical processor},
  author = {Zheng-Hao Liu and Yu Meng and Yu-Ze Wu and Ze-Yan Hao and Zhen-Peng Xu and Cheng-Jun Ai and Hai Wei and Kai Wen and Jing-Ling Chen and Jie Ma and Jin-Shi Xu and Chuan-Feng Li and Guang-Can Guo},
  journal= {arXiv preprint arXiv:2208.07794},
  year   = {2025}
}

Comments

20 pages, 9 figures. Clarified definitions. Discussed the potential path to the rigid contextuality test. Close to the published version

R2 v1 2026-06-25T01:44:35.736Z