Based on entanglement swapping, a quantum key distribution （QKD） scheme is proposed. In this scheme, the secret keys are formed by comparing initial Bell states and outcomes of entanglement swapping. Moreover, all i...Based on entanglement swapping, a quantum key distribution （QKD） scheme is proposed. In this scheme, the secret keys are formed by comparing initial Bell states and outcomes of entanglement swapping. Moreover, all initial Bell states prepared by Alice and Bob are completely arbitrary. As the classical information exchanged between two parties is very little, this QKD scheme has a high efficiency. In addition, in order to prevent eavesdropping, decoy particles are used.展开更多
A deterministic quantum key distribution scheme using two non-orthogonal entangled states is proposed. In the proposed scheme, communicators share key information by exchanging one travelling photon with two random an...A deterministic quantum key distribution scheme using two non-orthogonal entangled states is proposed. In the proposed scheme, communicators share key information by exchanging one travelling photon with two random and secret polarization angles. The security of the distributed key is guaranteed by three checking phases in three-way channel and the communicators＇ secret polarization angles.展开更多
We present a new quantum protocol for solving detectable Byzantine agreement problem between threeparties by employing one quantum key distribution protocol.The protocol is suggested by a special four-qubit entangleds...We present a new quantum protocol for solving detectable Byzantine agreement problem between threeparties by employing one quantum key distribution protocol.The protocol is suggested by a special four-qubit entangledstate instead of singlet states,which shows that singlet states are not necessary to achieve detectable Byzantine agreement.展开更多
We investigate the entanglement properties between two identical atoms with cascade configuration through the retarded dipole-dipole interaction in free space when their spatial separation is on the order of radiation...We investigate the entanglement properties between two identical atoms with cascade configuration through the retarded dipole-dipole interaction in free space when their spatial separation is on the order of radiation wavelength or less. We analyze the function of Hamiltonian induced by dipole-dipole interaction. By solving master equation, we show that the spontaneous emission induce entanglement and destroy entanglement too. We also show the long life time of entanglement within cascade configuration.展开更多
We propose a novel quantum key distribution scheme by using the SAM-OAM hybrid entangled state as the physical resource.To obtain this state,the polarization entangled photon pairs are created by the spontaneous param...We propose a novel quantum key distribution scheme by using the SAM-OAM hybrid entangled state as the physical resource.To obtain this state,the polarization entangled photon pairs are created by the spontaneous parametric down conversion process,and then,the q-plate acts as a SAM-to-OAM transverter to transform the polarization entangled pairs into the hybrid entangled pattern,which opens the possibility to exploit the features of the higher-dimensional space of OAM state to encode information.In the manipulation and encoding process,Alice performs the SAM measurement by modulating the polarization stateπ lθx on one photon,whereas Bob modulates the OAM sector state lx' on the other photon to encode his key elements using the designed holograms which is implemented by the computer-controlled SLM.With coincidence measurement,Alice could extract the key information.It is showed that N-based keys can be encoded with each pair of entangled photon,and this scheme is robust against Eve’s individual attack.Also,the MUBs are not used.Alice and Bob do not need the classical communication for the key recovery.展开更多
文摘Based on entanglement swapping, a quantum key distribution （QKD） scheme is proposed. In this scheme, the secret keys are formed by comparing initial Bell states and outcomes of entanglement swapping. Moreover, all initial Bell states prepared by Alice and Bob are completely arbitrary. As the classical information exchanged between two parties is very little, this QKD scheme has a high efficiency. In addition, in order to prevent eavesdropping, decoy particles are used.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 60472018 and 10547125
文摘A deterministic quantum key distribution scheme using two non-orthogonal entangled states is proposed. In the proposed scheme, communicators share key information by exchanging one travelling photon with two random and secret polarization angles. The security of the distributed key is guaranteed by three checking phases in three-way channel and the communicators＇ secret polarization angles.
基金Supported by National Natural Science Foundation of China under Grant Nos.60873191,60903152,and 60821001SRFDP under Grant No.200800131016+5 种基金Beijing Nova Program under Grant No.2008B51Key Project of Chinese Ministry of Education under Grant No.109014Beijing Natural Science Foundation under Grant No.4072020China Postdoctoral Science Foundation under Grant No.20090450018National Laboratory for Modern Communications Science Foundation of China under Grant No.9140C1101010601ISN Open Foundation
文摘We present a new quantum protocol for solving detectable Byzantine agreement problem between threeparties by employing one quantum key distribution protocol.The protocol is suggested by a special four-qubit entangledstate instead of singlet states,which shows that singlet states are not necessary to achieve detectable Byzantine agreement.
基金Supported by Natural Science Foundation for Young Scientists of Shanxi Province of China under Grant No. 2009021005
文摘We investigate the entanglement properties between two identical atoms with cascade configuration through the retarded dipole-dipole interaction in free space when their spatial separation is on the order of radiation wavelength or less. We analyze the function of Hamiltonian induced by dipole-dipole interaction. By solving master equation, we show that the spontaneous emission induce entanglement and destroy entanglement too. We also show the long life time of entanglement within cascade configuration.
基金supported by the National Cryptography Development Foundation of China(Grant No.MMJJ201401011)the Science and Technology Program of Guangzhou,China(Grant Nos.2013J4500095 and 2014J4100050)
文摘We propose a novel quantum key distribution scheme by using the SAM-OAM hybrid entangled state as the physical resource.To obtain this state,the polarization entangled photon pairs are created by the spontaneous parametric down conversion process,and then,the q-plate acts as a SAM-to-OAM transverter to transform the polarization entangled pairs into the hybrid entangled pattern,which opens the possibility to exploit the features of the higher-dimensional space of OAM state to encode information.In the manipulation and encoding process,Alice performs the SAM measurement by modulating the polarization stateπ lθx on one photon,whereas Bob modulates the OAM sector state lx' on the other photon to encode his key elements using the designed holograms which is implemented by the computer-controlled SLM.With coincidence measurement,Alice could extract the key information.It is showed that N-based keys can be encoded with each pair of entangled photon,and this scheme is robust against Eve’s individual attack.Also,the MUBs are not used.Alice and Bob do not need the classical communication for the key recovery.
