Observation of Genuine High-dimensional Multi-partite Non-locality in Entangled Photon States

Xiao-Min Hu; Cen-Xiao Huang; Nicola d'Alessandro; Gabriele Cobucci; Chao Zhang; Yu Guo; Yun-Feng Huang; Chuan-Feng Li; Guang-Can Guo; Xiaoqin Gao; Marcus Huber; Armin Tavakoli; Bi-Heng Liu

doi:10.1038/s41467-025-59717-y

Observation of Genuine High-dimensional Multi-partite Non-locality in Entangled Photon States

Nat Commun. 2025 May 30;16(1):5017. doi: 10.1038/s41467-025-59717-y.

Authors

Xiao-Min Hu^#^{1

2

3}, Cen-Xiao Huang^#^{1

2

3}, Nicola d'Alessandro⁴, Gabriele Cobucci⁴, Chao Zhang^{1

2}, Yu Guo^{1

2

3}, Yun-Feng Huang^{1

2

3}, Chuan-Feng Li^{1

2

3}, Guang-Can Guo^{1

2

3}, Xiaoqin Gao^{5

6}, Marcus Huber^{7

8}, Armin Tavakoli⁹, Bi-Heng Liu^{10

11

12}

Affiliations

¹ Laboratory of Quantum Information, University of Science and Technology of China, Hefei, China.
² CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China.
³ Hefei National Laboratory, University of Science and Technology of China, Hefei, China.
⁴ Department of Physics and NanoLund, Lund University, Lund, Sweden.
⁵ National Key Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing, Jiangsu, China.
⁶ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu, China.
⁷ Vienna Center for Quantum Science and Technology, Atominstitut, Technische Universität Wien, Vienna, Austria.
⁸ Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna, Austria.
⁹ Department of Physics and NanoLund, Lund University, Lund, Sweden. armin.tavakoli@teorfys.lu.se.
¹⁰ Laboratory of Quantum Information, University of Science and Technology of China, Hefei, China. bhliu@ustc.edu.cn.
¹¹ CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China. bhliu@ustc.edu.cn.
¹² Hefei National Laboratory, University of Science and Technology of China, Hefei, China. bhliu@ustc.edu.cn.

^# Contributed equally.

Abstract

Quantum information science has leaped forward with the exploration of high-dimensional quantum systems, offering greater potential than traditional qubits in quantum communication and quantum computing. To advance the field of high-dimensional quantum technology, a significant effort is underway to progressively enhance the entanglement dimension between two particles. An alternative effective strategy involves not only increasing the dimensionality but also expanding the number of particles that are entangled. We present an experimental study demonstrating multi-partite quantum non-locality beyond qubit constraints, thus moving into the realm of strongly entangled high-dimensional multi-particle quantum systems. In the experiment, quantum states were encoded in the path degree of freedom (DoF) and controlled via polarization, enabling efficient operations in a two-dimensional plane to prepare three- and four-particle Greenberger-Horne-Zeilinger (GHZ) states in three-level systems. Our experimental results reveal ways in which high-dimensional systems can surpass qubits in terms of violating local-hidden-variable theories. Our realization of multiple complex and high-quality entanglement technologies is an important primary step for more complex quantum computing and communication protocols.