As the cornerstone of future information security,quantum key distribution(QKD)is evolving towards large-scale hybrid discrete-variable/continuous-variable(DV/CV)multi-domain quantum networks.Meanwhile,multicast-orien...As the cornerstone of future information security,quantum key distribution(QKD)is evolving towards large-scale hybrid discrete-variable/continuous-variable(DV/CV)multi-domain quantum networks.Meanwhile,multicast-oriented multi-party key negotiation is attracting increasing attention in quantum networks.However,the efficient key provision for multicast services over hybrid DV/CV multi-domain quantum networks remains challenging,due to the limited probability of service success and the inefficient utilization of key resources.Targeting these challenges,this study proposes two key-resource-aware multicast-oriented key provision strategies,namely the link distance-resource balanced key provision strategy and the maximum shared link key provision strategy.The proposed strategies are applicable to hybrid DV/CV multi-domain quantum networks,which are typically implemented by GG02-based intra-domain connections and BB84-based inter-domain connections.Furthermore,the multicast-oriented key provision model is formulated,based on which two heuristic algorithms are designed,i.e.,the shared link distance-resource(SLDR)dependent and the maximum shared link distance-resource(MSLDR)dependent multicast-oriented key provision algorithms.Simulation results verify the applicability of the designed algorithms across different multi-domain quantum networks,and demonstrate their superiority over the benchmark algorithms in terms of the success probability of multicast service requests,the number of shared links,and the key resource utilization.展开更多
A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some observers.In this paper,we discuss an n-partite chain network with...A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some observers.In this paper,we discuss an n-partite chain network with each of two neighboring observers sharing an arbitrary Bell state and all intermediate observers performing some positive-operator-valued measurements with parameterλ.The expressions of all post-measurement states between any two observers are obtained,and their quantifications of Bell nonlocality,Einstein-Podolsky-Rosen steering and entanglement with different ranges ofλare respectively detected and analyzed.展开更多
The Greenberger–Horne–Zeilinger(GHZ)paradox shows that it is possible to create a multipartite state involving three or more particles in which the measurement outcomes of the particles are correlated in a way that ...The Greenberger–Horne–Zeilinger(GHZ)paradox shows that it is possible to create a multipartite state involving three or more particles in which the measurement outcomes of the particles are correlated in a way that cannot be explained by classical physics.We extend it to witness quantum networks.We first extend the GHZ paradox to simultaneously verify the GHZ state and Einstein–Podolsky–Rosen states on triangle networks.We then extend the GHZ paradox to witness the entanglement of chain networks consisting of multiple GHZ states.All the present results are robust against the noise.展开更多
Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement dis...Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement distribution.To realize efficient quantum communication based on quantum discord,in this paper,we consider the practical advantages of continuous variables and propose a feasible continuous-variable quantum network coding scheme based on quantum discord.By means of entanglement distribution by separable states,it can achieve quantum entanglement distribution from sources to targets in a butterfly network.Compared with the representative discrete-variable quantum network coding schemes,the proposed continuous-variable quantum network coding scheme has a higher probability of entanglement distribution and defends against eavesdropping and forgery attacks.Particularly,the deduced relationship indicates that the increase in entanglement is less than or equal to quantum discord.展开更多
In many earlier works,perfect quantum state transmission over the butterfly network can be achieved via quantum network coding protocols with the assist of maximally entangled states.However,in actual quantum networks...In many earlier works,perfect quantum state transmission over the butterfly network can be achieved via quantum network coding protocols with the assist of maximally entangled states.However,in actual quantum networks,a maximally entangled state as auxiliary resource is hard to be obtained or easily turned into a non-maximally entangled state subject to all kinds of environmental noises.Therefore,we propose a more practical quantum network coding scheme with the assist of non-maximally entangled states.In this paper,a practical quantum network coding protocol over grail network is proposed,in which the non-maximally entangled resource is assisted and even the desired quantum state can be perfectly transmitted.The achievable rate region,security and practicability of the proposed protocol are discussed and analyzed.This practical quantum network coding protocol proposed over the grail network can be regarded as a useful attempt to help move the theory of quantum network coding towards practicability.展开更多
This paper presents a quantum network to implement the optimal 1→2 quantum cloning in 2 dimensions, including the optimal asymmetric universal, the optimal symmetric phase-covariant, and the asymmetric real state clo...This paper presents a quantum network to implement the optimal 1→2 quantum cloning in 2 dimensions, including the optimal asymmetric universal, the optimal symmetric phase-covariant, and the asymmetric real state cloning. By only choosing different angles of the single-qubit rotations, the quantum network can implement three optimal quantum cloning.展开更多
Although perfect quantum network coding has been proved to be achievable, it is stiU puzzling whether it is feasible whenever one or more of the channels are replaced by the hidden ones emerging from quantum entanglem...Although perfect quantum network coding has been proved to be achievable, it is stiU puzzling whether it is feasible whenever one or more of the channels are replaced by the hidden ones emerging from quantum entanglement. The question is answered in this paper. First, we propose a quantum network coding protocol over a butterfly network with two hidden channels. Second, we investigate a more generaJ situation, where d-level quantum letters are transmitted through the network containing arbitrarily distributed hidden channels, and prove that quantum network coding on such networks is still achievable.展开更多
An alternative scheme is proposed to transfer quantum states and prepare a quantum network in cavity QED. It is based on the interaction of a two-mode cavity field with a three-level V-type atom. In the scheme, the at...An alternative scheme is proposed to transfer quantum states and prepare a quantum network in cavity QED. It is based on the interaction of a two-mode cavity field with a three-level V-type atom. In the scheme, the atom-cavity field interaction is resonant, thus the time required to complete the quantum state transfer process is greatly shortened, which is very important in view of decoherence. Moreover, the present scheme does not require one mode of the cavities to be initially prepared in one-photon state, thus it is more experimentally feasible than the previous ones.展开更多
Quantum network coding is used to solve the congestion problem in quantum communication,which will promote the transmission efficiency of quantum information and the total throughput of quantum network.We propose a no...Quantum network coding is used to solve the congestion problem in quantum communication,which will promote the transmission efficiency of quantum information and the total throughput of quantum network.We propose a novel controlled quantum network coding without information loss.The effective transmission of quantum states on the butterfly network requires the consent form a third-party controller Charlie.Firstly,two pairs of threeparticle non-maximum entangled states are pre-shared between senders and controller.By adding auxiliary particles and local operations,the senders can predict whether a certain quantum state can be successfully transmitted within the butterfly network based on the Z-{10>,|1>}basis.Secondly,when trans-mission fails upon prediction,the quantum state will not be lost,and it will sill be held by the sender.Subsequently,the controller Charlie re-prepares another three-particle non-maximum entangled state to start a new round.When the predicted transmission is successful,the quantum state can be transmitted successfully within the butterfly network.If the receiver wants to receive the effective quantum state,the quantum measurements from Charlie are needed.Thirdly,when the transmission fails,Charlie does not need to integrate the X-{1+>,1->}basis to measure its own particles,by which quantum resources are saved.Charlie not only controls the effective transmission of quantum states,but also the usage of classical and quantum channels.Finally,the implementation of the quantum circuits,as well as a flow chart and safety analysis of our scheme,is proposed.展开更多
How to establish a secure and efficient quantum network coding algorithm isone of important research topics of quantum secure communications. Based on thebutterfly network model and the characteristics of easy prepara...How to establish a secure and efficient quantum network coding algorithm isone of important research topics of quantum secure communications. Based on thebutterfly network model and the characteristics of easy preparation of Bell states, a novelanti-noise quantum network coding protocol is proposed in this paper. The new protocolencodes and transmits classical information by virtue of Bell states. It can guarantee thetransparency of the intermediate nodes during information, so that the eavesdropper Evedisables to get any information even if he intercepts the transmitted quantum states. Inview of the inevitability of quantum noise in quantum channel used, this paper analyzesthe influence of four kinds of noises on the new protocol in detail further, and verifies theefficiency of the protocol under different noise by mathematical calculation and analysis.In addition, based on the detailed mathematical analysis, the protocol has functioned wellnot only on improving the efficiency of information transmission, throughput and linkutilization in the quantum network, but also on enhancing reliability and antieavesdroppingattacks.展开更多
We investigate the performances of the pairwise correlations（PCs） in different quantum networks consisting of fourwave mixers（FWMs） and beamsplitters（BSs）. PCs with quantum correlation in different quantum netwo...We investigate the performances of the pairwise correlations（PCs） in different quantum networks consisting of fourwave mixers（FWMs） and beamsplitters（BSs）. PCs with quantum correlation in different quantum networks can be verified by calculating the degree of relative intensity squeezing for any pair of all the output fields. More interestingly, the quantum correlation recovery and enhancement are present in the FWM＋BS network and the repulsion effect phenomena（signal（idler）-frequency mode cannot be quantum correlated with the other two idler（signal）-frequency modes simultaneously）between the PCs with quantum correlation are predicted in the FWM ＋ FWM and FWM ＋ FWM ＋ FWM networks. Our results presented here pave the way for the manipulation of the quantum correlation in quantum networks.展开更多
We present a full quantum network scheme using a modified BB84 protocol. Unlike other quantum network schemes, it allows quantum keys to be distributed between two arbitrary users with the help of an intermediary dete...We present a full quantum network scheme using a modified BB84 protocol. Unlike other quantum network schemes, it allows quantum keys to be distributed between two arbitrary users with the help of an intermediary detecting user. Moreover, it has good expansibility and prevents all potential attacks using loopholes in a detector, so it is more practical to apply. Because the fiber birefringence effects are automatically compensated, the scheme is distinctly stable in principle and in experiment. The simple components for every user make our scheme easier for many applications. The experimental results demonstrate the stability and feasibility of this scheme.展开更多
This article discusses the covariance correlation tensor (CCT) in quantum network theory for four Bell bases in detail. Furthermore, it gives the expression of the density operator in terms of CCT for a quantum networ...This article discusses the covariance correlation tensor (CCT) in quantum network theory for four Bell bases in detail. Furthermore, it gives the expression of the density operator in terms of CCT for a quantum network of three nodes, thus gives the criterion of entanglement for this case, i.e. the conditions of complete separability and partial separability for a given quantum state of three bodies. Finally it discusses the general case for the quantum network of nodes.展开更多
This article discusses the separability of the pure states and mixed states of the quantum network of two nodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum net...This article discusses the separability of the pure states and mixed states of the quantum network of two nodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum network theory, i.e. for a composite system consisting of two nodes. The covariance correlation tensor is equal to zero for all possible and .展开更多
In this paper we propose a scheme for transferring quantum states and preparing quantum networks. Compared with the previous schemes, this scheme is more efficient, since three or four-dimensional quantum states can b...In this paper we propose a scheme for transferring quantum states and preparing quantum networks. Compared with the previous schemes, this scheme is more efficient, since three or four-dimensional quantum states can be transferred with a single step and information interchange of three-dimensional quantum states can be realized, which is a significant improvement. It is based on the resonant interaction of a three-mode cavity field with an atom. As a consequence, the interaction time is shortened greatly. Furthermore, we give some discussions about the feasibility of the scheme.展开更多
As an innovative theory and technology,quantum network coding has become the research hotspot in quantum network communications.In this paper,a quantum remote state preparation scheme based on quantum network coding i...As an innovative theory and technology,quantum network coding has become the research hotspot in quantum network communications.In this paper,a quantum remote state preparation scheme based on quantum network coding is proposed.Comparing with the general quantum remote state preparation schemes,our proposed scheme brings an arbitrary unknown quantum state finally prepared remotely through the quantum network,by designing the appropriate encoding and decoding steps for quantum network coding.What is worth mentioning,from the network model,this scheme is built on the quantum k-pair network which is the expansion of the typical bottleneck network—butterfly network.Accordingly,it can be treated as an efficient quantum network preparation scheme due to the characteristics of network coding,and it also makes the proposed scheme more applicable to the large-scale quantum networks.In addition,the fact of an arbitrary unknown quantum state remotely prepared means that the senders do not need to know the desired quantum state.Thus,the security of the proposed scheme is higher.Moreover,this scheme can always achieve the success probability of 1 and 1-max flow of value k.Thus,the communication efficiency of the proposed scheme is higher.Therefore,the proposed scheme turns out to be practicable,secure and efficient,which helps to effectively enrich the theory of quantum remote state preparation.展开更多
An optimized quantum network design is demonstrated by realizing a state-multiplexing quantum light source via a dual-excitation configuration technique.This approach optimizes the usage of the finite wavelength spect...An optimized quantum network design is demonstrated by realizing a state-multiplexing quantum light source via a dual-excitation configuration technique.This approach optimizes the usage of the finite wavelength spectrum,facilitating the efficient expansion of entanglement-based fully-connected quantum networks across multiple users.展开更多
Dzyaloshiniskii-Moriya (DM) interaction in three directions (Dx, Dy and Dz) is used to generate entangled network from partially entangled states in the presence of the spin-orbit coupling. The effect of the spin coup...Dzyaloshiniskii-Moriya (DM) interaction in three directions (Dx, Dy and Dz) is used to generate entangled network from partially entangled states in the presence of the spin-orbit coupling. The effect of the spin coupling on the entanglement between any two nodes of the network is investigated. The entanglement is quantified using Woottores concurrence method. It is shown that the entanglement decays as the coupling increases. For larger values of the spin coupling, the entanglement oscillates within finite bounds. For the initially entangled channels, the upper bound does not exceed its initial value, whereas the entanglement reaches its maximum value for the channels generated via indirect interaction.展开更多
In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts...In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts the efficiency of quantum communication. Inspired by sharing idea of quantum secret sharing (QSS), which is based on three collaborative nodes with pre-shared GHZ (Greenberger-Horne-Zeilinger) states, we propose a quantum secret broadcast scheme to improve network performance. In a cluster net-work cored on three parties of QSS, three cluster heads with pre-shared GHZ states are senders, while cluster members are receivers. One cluster head encodes secret messages on auxiliary particles by performing certain operations on them with GHZ particles, then three cluster heads measure their own par-ticles and broadcast measurement results honestly. Based on the specific correlation of measurement results and secret messages, all receivers can re-cover the secret messages. Furthermore, to prevent eavesdropping, cluster heads can update an encoding key periodically. Analysis shows the proposed scheme is more efficient than previous schemes in wireless quantum net-works, especially when the number of receivers is larger. Besides, in the proposed scheme, attacks on quantum channel based on GHZ state can be detected, and eavesdroppers cannot recover messages correctly for lack of suitable decoding key.展开更多
As the first stage of the quantum Internet,quantum key distribution(QKD)networks hold the promise of providing long-term security for diverse users.Most existing QKD networks have been constructed based on independent...As the first stage of the quantum Internet,quantum key distribution(QKD)networks hold the promise of providing long-term security for diverse users.Most existing QKD networks have been constructed based on independent QKD protocols,and they commonly rely on the deployment of single-protocol trusted relay chains for long reach.Driven by the evolution of QKD protocols,large-scale QKD networking is expected to migrate from a single-protocol to a multi-protocol paradigm,during which some useful evolutionary elements for the later stages of the quantum Internet may be incorporated.In this work,we delve into a pivotal technique for large-scale QKD networking,namely,multi-protocol relay chaining.A multi-protocol relay chain is established by connecting a set of trusted/untrusted relays relying on multiple QKD protocols between a pair of QKD nodes.The structures of diverse multi-protocol relay chains are described,based on which the associated model is formulated and the policies are defined for the deployment of multi-protocol relay chains.Furthermore,we propose three multi-protocol relay chaining heuristics.Numerical simulations indicate that the designed heuristics can effectively reduce the number of trusted relays deployed and enhance the average security level versus the commonly used single-protocol trusted relay chaining methods on backbone network topologies.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62201276,62350001,U22B2026,and 62425105)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300701)the Key R&D Program(Industry Foresight and Key Core Technologies)of Jiangsu Province(Grant No.BE2022071)。
文摘As the cornerstone of future information security,quantum key distribution(QKD)is evolving towards large-scale hybrid discrete-variable/continuous-variable(DV/CV)multi-domain quantum networks.Meanwhile,multicast-oriented multi-party key negotiation is attracting increasing attention in quantum networks.However,the efficient key provision for multicast services over hybrid DV/CV multi-domain quantum networks remains challenging,due to the limited probability of service success and the inefficient utilization of key resources.Targeting these challenges,this study proposes two key-resource-aware multicast-oriented key provision strategies,namely the link distance-resource balanced key provision strategy and the maximum shared link key provision strategy.The proposed strategies are applicable to hybrid DV/CV multi-domain quantum networks,which are typically implemented by GG02-based intra-domain connections and BB84-based inter-domain connections.Furthermore,the multicast-oriented key provision model is formulated,based on which two heuristic algorithms are designed,i.e.,the shared link distance-resource(SLDR)dependent and the maximum shared link distance-resource(MSLDR)dependent multicast-oriented key provision algorithms.Simulation results verify the applicability of the designed algorithms across different multi-domain quantum networks,and demonstrate their superiority over the benchmark algorithms in terms of the success probability of multicast service requests,the number of shared links,and the key resource utilization.
基金supported by the National Natural Science Foundation of China(12171290,12071336)the Fundamental Research Program of Shanxi Province(202303021222242).
文摘A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some observers.In this paper,we discuss an n-partite chain network with each of two neighboring observers sharing an arbitrary Bell state and all intermediate observers performing some positive-operator-valued measurements with parameterλ.The expressions of all post-measurement states between any two observers are obtained,and their quantifications of Bell nonlocality,Einstein-Podolsky-Rosen steering and entanglement with different ranges ofλare respectively detected and analyzed.
基金supported by the National Natural Science Foundation of China(Nos.62172341,12204386)Sichuan Natural Science Foundation(Nos.2024NSFSC1365,2024NSFSC1375 and 2023NSFSC0447)。
文摘The Greenberger–Horne–Zeilinger(GHZ)paradox shows that it is possible to create a multipartite state involving three or more particles in which the measurement outcomes of the particles are correlated in a way that cannot be explained by classical physics.We extend it to witness quantum networks.We first extend the GHZ paradox to simultaneously verify the GHZ state and Einstein–Podolsky–Rosen states on triangle networks.We then extend the GHZ paradox to witness the entanglement of chain networks consisting of multiple GHZ states.All the present results are robust against the noise.
基金This project is supported by the National Natural Science Foundation of China(No.61571024,No.61971021)Aeronautical Science Foundation of China(No.2018ZC51016)the National Key Research and Development Program of China(No.2016YFC1000307)for valuable helps.
文摘Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement distribution.To realize efficient quantum communication based on quantum discord,in this paper,we consider the practical advantages of continuous variables and propose a feasible continuous-variable quantum network coding scheme based on quantum discord.By means of entanglement distribution by separable states,it can achieve quantum entanglement distribution from sources to targets in a butterfly network.Compared with the representative discrete-variable quantum network coding schemes,the proposed continuous-variable quantum network coding scheme has a higher probability of entanglement distribution and defends against eavesdropping and forgery attacks.Particularly,the deduced relationship indicates that the increase in entanglement is less than or equal to quantum discord.
基金supported by the National Natural Science Foundation of China(Grant Nos.61671087,92046001,61962009,61003287,61370188,61373131)the Scientific Research Common Program of Beijing Municipal Commission of Education(KM202010015009,KM201610015002)+6 种基金the Joint Funding Project of Beijing Municipal Commission of Education and Beijing Natural Science Fund Committee(KZ201710015010)the Initial Funding for the Doctoral Program of BIGC(27170120003/020)the Fok Ying Tung Education Foundation(Grant No.131067)the Fundamental Research Funds for the Central Universities(Grant No.2019XD-A02)the Fundamental Research Funds in Heilongjiang Provincial Universities(135509116)the Major Scientific and Technological Special Project of Guizhou Province(20183001)Huawei Technologies Co.Ltd.(No.YBN2020085019),PAPD and CICAEET funds.
文摘In many earlier works,perfect quantum state transmission over the butterfly network can be achieved via quantum network coding protocols with the assist of maximally entangled states.However,in actual quantum networks,a maximally entangled state as auxiliary resource is hard to be obtained or easily turned into a non-maximally entangled state subject to all kinds of environmental noises.Therefore,we propose a more practical quantum network coding scheme with the assist of non-maximally entangled states.In this paper,a practical quantum network coding protocol over grail network is proposed,in which the non-maximally entangled resource is assisted and even the desired quantum state can be perfectly transmitted.The achievable rate region,security and practicability of the proposed protocol are discussed and analyzed.This practical quantum network coding protocol proposed over the grail network can be regarded as a useful attempt to help move the theory of quantum network coding towards practicability.
基金supported by the National Natural Science Foundation of China (Grant No 10674001)also by the Program of the Education Department of Anhui Province (Grant No KJ2007A002)
文摘This paper presents a quantum network to implement the optimal 1→2 quantum cloning in 2 dimensions, including the optimal asymmetric universal, the optimal symmetric phase-covariant, and the asymmetric real state cloning. By only choosing different angles of the single-qubit rotations, the quantum network can implement three optimal quantum cloning.
基金Supported by the National Natural Science Foundation of China under Grant No.61300203
文摘Although perfect quantum network coding has been proved to be achievable, it is stiU puzzling whether it is feasible whenever one or more of the channels are replaced by the hidden ones emerging from quantum entanglement. The question is answered in this paper. First, we propose a quantum network coding protocol over a butterfly network with two hidden channels. Second, we investigate a more generaJ situation, where d-level quantum letters are transmitted through the network containing arbitrarily distributed hidden channels, and prove that quantum network coding on such networks is still achievable.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10225421 and 10674025
文摘An alternative scheme is proposed to transfer quantum states and prepare a quantum network in cavity QED. It is based on the interaction of a two-mode cavity field with a three-level V-type atom. In the scheme, the atom-cavity field interaction is resonant, thus the time required to complete the quantum state transfer process is greatly shortened, which is very important in view of decoherence. Moreover, the present scheme does not require one mode of the cavities to be initially prepared in one-photon state, thus it is more experimentally feasible than the previous ones.
基金This work is supported by NSFC(Grant Nos.92046001,61571024,61671087,61962009,61971021)the Aeronautical Science Foundation of China(2018ZC51016)+4 种基金the Fundamental Research Funds for the Central Universities(Grant No.2019XD-A02)the Open Foundation of Guizhou Provincial Key Laboratory of Public Big Data(Grant Nos.2018BDKFJJ018,2019BDKFJJ010,2019BDKFJJ014)the Open Research Project of the State Key Laboratory of Media Convergence and Communication,Communication University of China,China(Grant No.SKLMCC2020KF006)Huawei Technologies Co.Ltd(Grant No.YBN2020085019)the Scientific Research Foundation of North China University of Technology.
文摘Quantum network coding is used to solve the congestion problem in quantum communication,which will promote the transmission efficiency of quantum information and the total throughput of quantum network.We propose a novel controlled quantum network coding without information loss.The effective transmission of quantum states on the butterfly network requires the consent form a third-party controller Charlie.Firstly,two pairs of threeparticle non-maximum entangled states are pre-shared between senders and controller.By adding auxiliary particles and local operations,the senders can predict whether a certain quantum state can be successfully transmitted within the butterfly network based on the Z-{10>,|1>}basis.Secondly,when trans-mission fails upon prediction,the quantum state will not be lost,and it will sill be held by the sender.Subsequently,the controller Charlie re-prepares another three-particle non-maximum entangled state to start a new round.When the predicted transmission is successful,the quantum state can be transmitted successfully within the butterfly network.If the receiver wants to receive the effective quantum state,the quantum measurements from Charlie are needed.Thirdly,when the transmission fails,Charlie does not need to integrate the X-{1+>,1->}basis to measure its own particles,by which quantum resources are saved.Charlie not only controls the effective transmission of quantum states,but also the usage of classical and quantum channels.Finally,the implementation of the quantum circuits,as well as a flow chart and safety analysis of our scheme,is proposed.
文摘How to establish a secure and efficient quantum network coding algorithm isone of important research topics of quantum secure communications. Based on thebutterfly network model and the characteristics of easy preparation of Bell states, a novelanti-noise quantum network coding protocol is proposed in this paper. The new protocolencodes and transmits classical information by virtue of Bell states. It can guarantee thetransparency of the intermediate nodes during information, so that the eavesdropper Evedisables to get any information even if he intercepts the transmitted quantum states. Inview of the inevitability of quantum noise in quantum channel used, this paper analyzesthe influence of four kinds of noises on the new protocol in detail further, and verifies theefficiency of the protocol under different noise by mathematical calculation and analysis.In addition, based on the detailed mathematical analysis, the protocol has functioned wellnot only on improving the efficiency of information transmission, throughput and linkutilization in the quantum network, but also on enhancing reliability and antieavesdroppingattacks.
基金Project supported by the National Natural Science Foundation of China(Grants Nos.91436211,11374104,and 10974057)the Natural Science Foundation of Shanghai,China(Grant No.17ZR1442900)+5 种基金the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20130076110011)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,the Program for New Century Excellent Talents in University,China(Grant No.NCET-10-0383)the Shu Guang Project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation,China(Grant No.11SG26)the Shanghai Pujiang Program,China(Grant No.09PJ1404400)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,National Basic Research Program of China(Grant No.2016YFA0302103)the Program of State Key Laboratory of Advanced 207 Optical Communication Systems and Networks,China(Grant No.2016GZKF0JT003)
文摘We investigate the performances of the pairwise correlations（PCs） in different quantum networks consisting of fourwave mixers（FWMs） and beamsplitters（BSs）. PCs with quantum correlation in different quantum networks can be verified by calculating the degree of relative intensity squeezing for any pair of all the output fields. More interestingly, the quantum correlation recovery and enhancement are present in the FWM＋BS network and the repulsion effect phenomena（signal（idler）-frequency mode cannot be quantum correlated with the other two idler（signal）-frequency modes simultaneously）between the PCs with quantum correlation are predicted in the FWM ＋ FWM and FWM ＋ FWM ＋ FWM networks. Our results presented here pave the way for the manipulation of the quantum correlation in quantum networks.
基金Project supported by the National Natural Science Foundation of China(Grant No.61178010)the Fundamental Research Funds for the Central Universities(Grant No.bupt 2014TS01)+1 种基金the Fund of the State Key Laboratory of Information Photonics and Optical Communications(Grant No.201318)(Beijing University of Posts and Telecommunications)the National Program for Basic Research of China(Grant No.2010CB923202)
文摘We present a full quantum network scheme using a modified BB84 protocol. Unlike other quantum network schemes, it allows quantum keys to be distributed between two arbitrary users with the help of an intermediary detecting user. Moreover, it has good expansibility and prevents all potential attacks using loopholes in a detector, so it is more practical to apply. Because the fiber birefringence effects are automatically compensated, the scheme is distinctly stable in principle and in experiment. The simple components for every user make our scheme easier for many applications. The experimental results demonstrate the stability and feasibility of this scheme.
文摘This article discusses the covariance correlation tensor (CCT) in quantum network theory for four Bell bases in detail. Furthermore, it gives the expression of the density operator in terms of CCT for a quantum network of three nodes, thus gives the criterion of entanglement for this case, i.e. the conditions of complete separability and partial separability for a given quantum state of three bodies. Finally it discusses the general case for the quantum network of nodes.
文摘This article discusses the separability of the pure states and mixed states of the quantum network of two nodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum network theory, i.e. for a composite system consisting of two nodes. The covariance correlation tensor is equal to zero for all possible and .
基金Supported by the National Natural Science Foundation of China under Grant No.10974028Fujian Provincial Natural Science Foundation of China under Grant No.2009J06002
文摘In this paper we propose a scheme for transferring quantum states and preparing quantum networks. Compared with the previous schemes, this scheme is more efficient, since three or four-dimensional quantum states can be transferred with a single step and information interchange of three-dimensional quantum states can be realized, which is a significant improvement. It is based on the resonant interaction of a three-mode cavity field with an atom. As a consequence, the interaction time is shortened greatly. Furthermore, we give some discussions about the feasibility of the scheme.
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.61370188,62176273,61962009)the Scientific Research Common Program of Beijing Municipal Commission of Education(KM202010015009,KM202110015004)+4 种基金Initial Funding for the Doctoral Program of BIGC(27170121001/009)the Open Foundation of State key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications)(SKLNST-2021-1-16)the Open Fund of Advanced Cryptography and System Security Key Laboratory of Sichuan Province(Grant No.SKLACSS-202101)the Fundamental Research Funds for Beijing Municipal Commission of Education,Beijing Urban Governance Research Base of North China University of Technologythe Natural Science Foundation of Inner Mongolia(2021MS06006).
文摘As an innovative theory and technology,quantum network coding has become the research hotspot in quantum network communications.In this paper,a quantum remote state preparation scheme based on quantum network coding is proposed.Comparing with the general quantum remote state preparation schemes,our proposed scheme brings an arbitrary unknown quantum state finally prepared remotely through the quantum network,by designing the appropriate encoding and decoding steps for quantum network coding.What is worth mentioning,from the network model,this scheme is built on the quantum k-pair network which is the expansion of the typical bottleneck network—butterfly network.Accordingly,it can be treated as an efficient quantum network preparation scheme due to the characteristics of network coding,and it also makes the proposed scheme more applicable to the large-scale quantum networks.In addition,the fact of an arbitrary unknown quantum state remotely prepared means that the senders do not need to know the desired quantum state.Thus,the security of the proposed scheme is higher.Moreover,this scheme can always achieve the success probability of 1 and 1-max flow of value k.Thus,the communication efficiency of the proposed scheme is higher.Therefore,the proposed scheme turns out to be practicable,secure and efficient,which helps to effectively enrich the theory of quantum remote state preparation.
文摘An optimized quantum network design is demonstrated by realizing a state-multiplexing quantum light source via a dual-excitation configuration technique.This approach optimizes the usage of the finite wavelength spectrum,facilitating the efficient expansion of entanglement-based fully-connected quantum networks across multiple users.
文摘Dzyaloshiniskii-Moriya (DM) interaction in three directions (Dx, Dy and Dz) is used to generate entangled network from partially entangled states in the presence of the spin-orbit coupling. The effect of the spin coupling on the entanglement between any two nodes of the network is investigated. The entanglement is quantified using Woottores concurrence method. It is shown that the entanglement decays as the coupling increases. For larger values of the spin coupling, the entanglement oscillates within finite bounds. For the initially entangled channels, the upper bound does not exceed its initial value, whereas the entanglement reaches its maximum value for the channels generated via indirect interaction.
文摘In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts the efficiency of quantum communication. Inspired by sharing idea of quantum secret sharing (QSS), which is based on three collaborative nodes with pre-shared GHZ (Greenberger-Horne-Zeilinger) states, we propose a quantum secret broadcast scheme to improve network performance. In a cluster net-work cored on three parties of QSS, three cluster heads with pre-shared GHZ states are senders, while cluster members are receivers. One cluster head encodes secret messages on auxiliary particles by performing certain operations on them with GHZ particles, then three cluster heads measure their own par-ticles and broadcast measurement results honestly. Based on the specific correlation of measurement results and secret messages, all receivers can re-cover the secret messages. Furthermore, to prevent eavesdropping, cluster heads can update an encoding key periodically. Analysis shows the proposed scheme is more efficient than previous schemes in wireless quantum net-works, especially when the number of receivers is larger. Besides, in the proposed scheme, attacks on quantum channel based on GHZ state can be detected, and eavesdroppers cannot recover messages correctly for lack of suitable decoding key.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.62201276,62350001,U22B2026,and 62471248)Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300701)+1 种基金the Key R&D Program(Industry Foresight and Key Core Technologies)of Jiangsu Province(Grant No.BE2022071)Natural Science Research of Jiangsu Higher Education Institutions of China(Grant No.22KJB510007)。
文摘As the first stage of the quantum Internet,quantum key distribution(QKD)networks hold the promise of providing long-term security for diverse users.Most existing QKD networks have been constructed based on independent QKD protocols,and they commonly rely on the deployment of single-protocol trusted relay chains for long reach.Driven by the evolution of QKD protocols,large-scale QKD networking is expected to migrate from a single-protocol to a multi-protocol paradigm,during which some useful evolutionary elements for the later stages of the quantum Internet may be incorporated.In this work,we delve into a pivotal technique for large-scale QKD networking,namely,multi-protocol relay chaining.A multi-protocol relay chain is established by connecting a set of trusted/untrusted relays relying on multiple QKD protocols between a pair of QKD nodes.The structures of diverse multi-protocol relay chains are described,based on which the associated model is formulated and the policies are defined for the deployment of multi-protocol relay chains.Furthermore,we propose three multi-protocol relay chaining heuristics.Numerical simulations indicate that the designed heuristics can effectively reduce the number of trusted relays deployed and enhance the average security level versus the commonly used single-protocol trusted relay chaining methods on backbone network topologies.
