In this paper, two schemes for teleporting an unknown four-particle entangled W state is proposed. In the first scheme, two partial entangled four-particle states are used as quantum channels, while in the second sche...In this paper, two schemes for teleporting an unknown four-particle entangled W state is proposed. In the first scheme, two partial entangled four-particle states are used as quantum channels, while in the second scheme,four non-maximally entangled particle pairs are considered as quantum channels. It is shown that the teleportation can be successfully realized with certain probability, for both schemes, if a receiver adopts some appropriate unitary transformations. It is also shown that the successful probabilities of these two schemes are different.展开更多
This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication （DQC） is proposed. The sender can use the proposed...This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication （DQC） is proposed. The sender can use the proposed coding function to encode his/her message, and the receiver can perform the imperfect Bell measurement to obtain the sender＇s message. In comparison to the existing DQC protocols that also use the W class state, the proposed protocol is more efficient and also more practical within today＇s technology. Moreover, the security of this protocol is analyzed to show that any eavesdropper will be detected with a very high probability under both the ideal and the noisy quantum channel.展开更多
This paper proposes a scheme for entanglement concentration of unknown triparticle W class states with a certain probability. This protocol is mainly based on the coincidences of single-photon detectors and requires s...This paper proposes a scheme for entanglement concentration of unknown triparticle W class states with a certain probability. This protocol is mainly based on the coincidences of single-photon detectors and requires single-photon detectors and linear optical elements. The scheme is feasible within current technology.展开更多
We present a quantum secure communication scheme using three-qubit W state. It is unnecessary for the present scheme to use alternative measurement or Bell basis measurement. Compared with the quantum secure direct co...We present a quantum secure communication scheme using three-qubit W state. It is unnecessary for the present scheme to use alternative measurement or Bell basis measurement. Compared with the quantum secure direct communication scheme proposed by Cao et at. [H.J. Cao and H.S. Song, Chin. Phys. Lett. 23 （2006） 290], in our scheme, the detection probability for an eavesdropper＇s attack increases from 8.3% to 25%. We also show that our scheme is secure for a noise quantum channel.展开更多
Telecloning and its reverse process, referred to as remote quantum-information concentration (RQIC), have been attracting considerable interest because of their potential applications in quantum-information processing...Telecloning and its reverse process, referred to as remote quantum-information concentration (RQIC), have been attracting considerable interest because of their potential applications in quantum-information processing. The previous RQIC protocols were focused on the reverse process of the optimal universal telecloning. We here study the reverse process of ancilla-free phase-covariant telecloning (AFPCT). It is shown that the quantum information originally distributed into two spatially separated qubits from a single qubit via the optimal AFPCT procedure can be remotely concentrated back to a single qubit with a certain probability by using an asymmetric W state as the quantum channel.展开更多
We present a universal way to concentrate an arbitrary N-particle less-entangled W state into a maximally entangled W state with different parity check gates.It comprises two protocols.The first protocol is based on t...We present a universal way to concentrate an arbitrary N-particle less-entangled W state into a maximally entangled W state with different parity check gates.It comprises two protocols.The first protocol is based on the linear optical elements,say the partial parity check gate and the second protocol uses the quantum nondemolition measurement to construct the complete parity check gate.Both protocols can achieve the concentration task.These protocols have several advantages.First,they can obtain a maximally entangled W state only with the help of some single photons,which greatly reduces the number of entanglement resources.Second,in the first protocol,only linear optical elements are required,which is feasible with current techniques.Third,the second protocol can be repeated to perform the concentration step and obtain a higher success probability.All these advantages make it quite useful in current quantum communication and computation applications.展开更多
A theoretical scheme of quantum secure direct communication using teleportation is proposed. In the scheme, the sender needs to prepare a class of three-particle W states to use as quantum channel. The two communicato...A theoretical scheme of quantum secure direct communication using teleportation is proposed. In the scheme, the sender needs to prepare a class of three-particle W states to use as quantum channel. The two communicators may communicate after they test the security of the quantum channel. The security of the protocol is ensured by quantum entanglement and quantum no-cloning theorem. The receiver can obtain the secret message determinately if the quantum channel is secure.展开更多
文摘In this paper, two schemes for teleporting an unknown four-particle entangled W state is proposed. In the first scheme, two partial entangled four-particle states are used as quantum channels, while in the second scheme,four non-maximally entangled particle pairs are considered as quantum channels. It is shown that the teleportation can be successfully realized with certain probability, for both schemes, if a receiver adopts some appropriate unitary transformations. It is also shown that the successful probabilities of these two schemes are different.
基金supported by the National Science Council of the Republic of China(Grant No.NSC 98-2221-E-006-097-MY3)
文摘This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication （DQC） is proposed. The sender can use the proposed coding function to encode his/her message, and the receiver can perform the imperfect Bell measurement to obtain the sender＇s message. In comparison to the existing DQC protocols that also use the W class state, the proposed protocol is more efficient and also more practical within today＇s technology. Moreover, the security of this protocol is analyzed to show that any eavesdropper will be detected with a very high probability under both the ideal and the noisy quantum channel.
基金Project supported by the Natural Science Foundation of the Education Department of Anhui Province, China （Grant No 2006kj070A） and Anhui Provincial Natural Science Foundation, China （Grant No 03042401） and the Talent Foundation of Anhui University, China.
文摘This paper proposes a scheme for entanglement concentration of unknown triparticle W class states with a certain probability. This protocol is mainly based on the coincidences of single-photon detectors and requires single-photon detectors and linear optical elements. The scheme is feasible within current technology.
基金The project supported by National Natural Science Foundation of China under Grant No. 60472032
文摘We present a quantum secure communication scheme using three-qubit W state. It is unnecessary for the present scheme to use alternative measurement or Bell basis measurement. Compared with the quantum secure direct communication scheme proposed by Cao et at. [H.J. Cao and H.S. Song, Chin. Phys. Lett. 23 （2006） 290], in our scheme, the detection probability for an eavesdropper＇s attack increases from 8.3% to 25%. We also show that our scheme is secure for a noise quantum channel.
文摘Telecloning and its reverse process, referred to as remote quantum-information concentration (RQIC), have been attracting considerable interest because of their potential applications in quantum-information processing. The previous RQIC protocols were focused on the reverse process of the optimal universal telecloning. We here study the reverse process of ancilla-free phase-covariant telecloning (AFPCT). It is shown that the quantum information originally distributed into two spatially separated qubits from a single qubit via the optimal AFPCT procedure can be remotely concentrated back to a single qubit with a certain probability by using an asymmetric W state as the quantum channel.
基金supported by the National Natural Science Foundation of China(Grant Nos.11474168and 61401222)the Qing Lan Project in Jiangsu Province+2 种基金Specialized Research Fund for the Doctoral Program of Higher Education(Grant No20113223120002)University Natural Science Research Project of Jiangsu Province(Grant No.11KJB510016)the Priority Academic Development Program of Jiangsu Higher Education Institutions,China
文摘We present a universal way to concentrate an arbitrary N-particle less-entangled W state into a maximally entangled W state with different parity check gates.It comprises two protocols.The first protocol is based on the linear optical elements,say the partial parity check gate and the second protocol uses the quantum nondemolition measurement to construct the complete parity check gate.Both protocols can achieve the concentration task.These protocols have several advantages.First,they can obtain a maximally entangled W state only with the help of some single photons,which greatly reduces the number of entanglement resources.Second,in the first protocol,only linear optical elements are required,which is feasible with current techniques.Third,the second protocol can be repeated to perform the concentration step and obtain a higher success probability.All these advantages make it quite useful in current quantum communication and computation applications.
基金National Natural Science Foundation of China under Grant Nos.10647101 and 10704011
文摘A theoretical scheme of quantum secure direct communication using teleportation is proposed. In the scheme, the sender needs to prepare a class of three-particle W states to use as quantum channel. The two communicators may communicate after they test the security of the quantum channel. The security of the protocol is ensured by quantum entanglement and quantum no-cloning theorem. The receiver can obtain the secret message determinately if the quantum channel is secure.
