The reliable detection of entanglement plays a crucial role in the construction of quantum networks.The conventional entanglement witness(EW)method has high requirements for measurement device and relies on reliable i...The reliable detection of entanglement plays a crucial role in the construction of quantum networks.The conventional entanglement witness(EW)method has high requirements for measurement device and relies on reliable implementation of the measurement.With unreliable measurement device,EW process can be easily attacked by eavesdroppers,which can lead to incorrect entanglement detection results.Therefore,a feasible and secure measurement device independent entanglement witness(MDIEW)method is desired for constructing quantum networks.Here,we detect the continuous variable entanglement by a MDIEW in a quantum network.It is demonstrated that the conventional EW method can be affected when the local oscillator intensity is changed,while the MDIEW method can detect entanglement between users without being affected.Our results provide a trustworthy method to detect entanglement,which is an important step for constructing secure quantum networks.展开更多
基金funded by the National Natural Science Foundation of China(NSFC,No.12225404,No.12434014,No.11874155,No.91436211,No.11374104,No.12174110,No.12574390,and No.12474357)Innovation Program for Quantum Science and Technology(No.2024ZD0302402)+10 种基金Innovation Program of Shanghai Municipal Education Commission(No.2021-01-07-00-08-E00100)Program of Shanghai Academic Research Leader(No.22XD1400700)Basic Research Project in Quantum Science of Shanghai Action Plan for Science Technology and Innovation(No.24LZ1400700)Fundamental Research Funds for the Central UniversitiesBasic Research Project of Shanghai Science and Technology Commission(No.20JC1416100)Natural Science Foundation of Shanghai(No.17ZR1442900,No.24ZR1418700)Minhang Leading Talents(No.201971)Shanghai Sailing Program(No.21YF1410800)Natural Science Foundation of Chongqing(No.CSTB2022NSCQ-MSX0893)Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01)and the 111 project(B12024).
文摘The reliable detection of entanglement plays a crucial role in the construction of quantum networks.The conventional entanglement witness(EW)method has high requirements for measurement device and relies on reliable implementation of the measurement.With unreliable measurement device,EW process can be easily attacked by eavesdroppers,which can lead to incorrect entanglement detection results.Therefore,a feasible and secure measurement device independent entanglement witness(MDIEW)method is desired for constructing quantum networks.Here,we detect the continuous variable entanglement by a MDIEW in a quantum network.It is demonstrated that the conventional EW method can be affected when the local oscillator intensity is changed,while the MDIEW method can detect entanglement between users without being affected.Our results provide a trustworthy method to detect entanglement,which is an important step for constructing secure quantum networks.
