Entropy (Nov 2021)

Experimental Investigation of the Robustness of a New Bell-Type Inequality of Triphoton GHZ States in Open Systems

  • Jiaqiang Zhao,
  • Meijiao Wang,
  • Lianzhen Cao,
  • Yang Yang,
  • Xia Liu,
  • Qinwei Zhang,
  • Huaixin Lu,
  • Kellie Ann Driscoll

DOI
https://doi.org/10.3390/e23111514
Journal volume & issue
Vol. 23, no. 11
p. 1514

Abstract

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Knowing the level of entanglement robustness against quantum bit loss or decoherence mechanisms is an important issue for any application of quantum information. Fidelity of states can be used to judge whether there is entanglement in multi-particle systems. It is well known that quantum channel security in QKD can be estimated by measuring the robustness of Bell-type inequality against noise. We experimentally investigate a new Bell-type inequality (NBTI) in the three-photon Greenberger–Horne–Zeilinger (GHZ) states with different levels of spin-flip noise. The results show that the fidelity and the degree of violation of the NBTI decrease monotonically with the increase of noise intensity. They also provide a method to judge whether there is entanglement in three-particle mixed states.

Keywords