Robust Self-Testing of Multiparticle Entanglement

TitleRobust Self-Testing of Multiparticle Entanglement
Publication TypeJournal Article
Year of Publication2021
AuthorsWu, D, Zhao, Q, Gu, X-M, Zhong, H-S, Zhou, Y, Peng, L-C, Qin, J, Luo, Y-H, Chen, K, Li, L, Le Liu, N-, Lu, C-Y, Pan, J-W
JournalPhys. Rev. Lett.
Date Published12/7/2021

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. Due to 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 multi-particle quantum entanglement. We prepare two examples of four-photon graph states, the Greenberger-Horne-Zeilinger (GHZ) 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.