Chinese Journal of Quantum Electronics ›› 2023, Vol. 40 ›› Issue (6): 943-951.doi: 10.3969/j.issn.1007-5461.2023.06.014

• Quantum Optics • Previous Articles     Next Articles

Deterministic entanglement purification for decohered GHZ state assisted by spatial entanglement

ZHU Mengzheng* , SU Mengyuan, GONG Pifeng, ZHANG Jinfeng   

  1. ( School of Physics & Electronic Information, Huaibei Normal University, Huaibei 235000, China )
  • Received:2022-01-17 Revised:2022-03-17 Published:2023-11-28 Online:2023-11-28

Abstract: A deterministic entanglement purification protocol (EPP) for polarization decohered Greenberger-Horne-Zeilinger (GHZ) state is presented based on linear optical elements such as polarization beam splitter and half-wave plate. The proposed EPP makes use of spatial entanglement as an additional resource to purify polarization entanglement, and its essence is to transfer the bit-flip and phase-flip errors from polarization degree of freedom (DOF) to spatial one using the methods of linear optics and hyper-entanglement. The entanglement purification scheme can be implemented without knowing any parameters of the low-entanglement GHZ state to be purified, without converting phase flip errors to bit flips for purification, introducing the nonlinear effects. According to the proposed EPP, just in a purification step, both the bit-flip and phase-flip errors in the polarization mixed states can be deterministically corrected by using additional entanglement DOF in spatial mode, which greatly enhances the experimental feasibility of this scheme.

Key words: quantum optics, entanglement purification, quantum communications, hyper-entanglement

CLC Number: