Robust self-testing of multiparticle entanglement

• Main Authors: Wu, Dian, Zhao, Qi, Gu, Xue-Mei, Zhong, Han-Sen, Zhou, You, Peng, Li-Chao, Qin, Jian, Luo, Yi-Han, Chen, Kai, Li, Li, Liu, Nai-Le, Lu, Chao-Yang, Pan, Jian-Wei
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2022
• Subjects: Science::Physics; Quantum; Entanglement Detection
• Online Access: https://hdl.handle.net/10356/161256
• Institution: Nanyang Technological University

Quantum self-testing is a device-independent way to certify quantum states and measurements using only the input-output statistics, with minimal assumptions about the quantum devices. Because of the high demand on tolerable noise, however, experimental self-testing was limited to two-photon systems. Here, we demonstrate the first robust self-testing for multiphoton genuinely entangled quantum states. We prepare two examples of four-photon graph states, the Greenberger-Horne-Zeilinger states with a fidelity of 0.957(2) and the linear cluster states with a fidelity of 0.945(2). Based on the observed input-output statistics, we certify the genuine four-photon entanglement and further estimate their qualities with respect to realistic noise in a device-independent manner.