We investigate the continuous variable quomtum teleportation in atmosphere channels. The beam-wandering mode/is employed to analyze the teleportation of the unknown single-mode coherent state. Two methods, one is dete...We investigate the continuous variable quomtum teleportation in atmosphere channels. The beam-wandering mode/is employed to analyze the teleportation of the unknown single-mode coherent state. Two methods, one is deterministic by increasing the aperture size of the detecting device and one is probabilistic by entanglement distillation, are proposed to improve the teleportation fidelity in the presence of atmosphere noises.展开更多
In this paper, classical and continuous variable (CV) quantum neural network hybrid multi-classifiers are presented using the MNIST dataset. Currently available classifiers can classify only up to two classes. The pro...In this paper, classical and continuous variable (CV) quantum neural network hybrid multi-classifiers are presented using the MNIST dataset. Currently available classifiers can classify only up to two classes. The proposed architecture allows networks to classify classes up to n<sup>m</sup> classes, where n represents cutoff dimension and m the number of qumodes on photonic quantum computers. The combination of cutoff dimension and probability measurement method in the CV model allows a quantum circuit to produce output vectors of size n<sup>m</sup>. They are then interpreted as one-hot encoded labels, padded with n<sup>m</sup> - 10 zeros. The total of seven different classifiers is built using 2, 3, …, 6, and 8-qumodes on photonic quantum computing simulators, based on the binary classifier architecture proposed in “Continuous variable quantum neural networks” [1]. They are composed of a classical feed-forward neural network, a quantum data encoding circuit, and a CV quantum neural network circuit. On a truncated MNIST dataset of 600 samples, a 4-qumode hybrid classifier achieves 100% training accuracy.展开更多
Continuous-variable quantum key distribution(CV QKD)using optical coherent detectors is practically favorable due to its low implementation cost,flexibility of wavelength division multiplexing,and compatibility with s...Continuous-variable quantum key distribution(CV QKD)using optical coherent detectors is practically favorable due to its low implementation cost,flexibility of wavelength division multiplexing,and compatibility with standard coherent communication technologies.However,the security analysis and parameter estimation of CV QKD are complicated due to the infinite-dimensional latent Hilbert space.Also,the transmission of strong reference pulses undermines the security and complicates the experiments.In this work,we tackle these two problems by presenting a time-bin-encoding CV protocol with a simple phase-error-based security analysis valid under general coherent attacks.With the key encoded into the relative intensity between two optical modes,the need for global references is removed.Furthermore,phase randomization can be introduced to decouple the security analysis of different photon-number components.We can hence tag the photon number for each round,effectively estimate the associated privacy using a carefully designed coherent-detection method,and independently extract encryption keys from each component.Simulations manifest that the protocol using multi-photon components increases the key rate by two orders of magnitude compared to the one using only the single-photon component.Meanwhile,the protocol with four-intensity decoy analysis is sufficient to yield tight parameter estimation with a short-distance key-rate performance comparable to the best Bennett-Brassard-1984 implementation.展开更多
With the rapid spread of Internet technology,e-commerce is gradually becoming an integral part of the modern business models.The e-commerce transactions should obey integrity,authentication,nonrepudiation,traceability...With the rapid spread of Internet technology,e-commerce is gradually becoming an integral part of the modern business models.The e-commerce transactions should obey integrity,authentication,nonrepudiation,traceability,and impartiality.Here,we propose and demonstrate a complete continuous-variable quantum e-commerce scheme,which involves subscription,payment,transport,and reception protocols among five parties.To this end,a simple,efficient quantum digital payment scheme is proposed.Furthermore,we streamline the entire e-commerce process by eliminating the private amplification step in the pre-distribution of keys.We achieve a contract signing rate of 1.51×10^(3)times per second for a 33 kilobits contract,and a payment rate of 2.70×10^(3)times per second over 80 km of single-mode fiber.Our results can support 411 times complete transactions per second,including three contract signings and two separate monetary payments.The proposed scheme takes into account the compatibility with existing e-commerce platforms to ensure a smooth transition and provides a practical solution for quantum e-commerce at metropolitan distances.展开更多
The preparation of multipartite entangled states is the prerequisite for exploring quantum information networks and quantum computation.In this paper,we review the experimental progress in the preparation of cluster s...The preparation of multipartite entangled states is the prerequisite for exploring quantum information networks and quantum computation.In this paper,we review the experimental progress in the preparation of cluster states and multi-color entangled states with continuous variables.The preparation of lager scale multipartite entangled state provide valuable quantum resources to implement more complex quantum informational tasks.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574400,U1304613,11204197,11204379and 11074244
文摘We investigate the continuous variable quomtum teleportation in atmosphere channels. The beam-wandering mode/is employed to analyze the teleportation of the unknown single-mode coherent state. Two methods, one is deterministic by increasing the aperture size of the detecting device and one is probabilistic by entanglement distillation, are proposed to improve the teleportation fidelity in the presence of atmosphere noises.
文摘In this paper, classical and continuous variable (CV) quantum neural network hybrid multi-classifiers are presented using the MNIST dataset. Currently available classifiers can classify only up to two classes. The proposed architecture allows networks to classify classes up to n<sup>m</sup> classes, where n represents cutoff dimension and m the number of qumodes on photonic quantum computers. The combination of cutoff dimension and probability measurement method in the CV model allows a quantum circuit to produce output vectors of size n<sup>m</sup>. They are then interpreted as one-hot encoded labels, padded with n<sup>m</sup> - 10 zeros. The total of seven different classifiers is built using 2, 3, …, 6, and 8-qumodes on photonic quantum computing simulators, based on the binary classifier architecture proposed in “Continuous variable quantum neural networks” [1]. They are composed of a classical feed-forward neural network, a quantum data encoding circuit, and a CV quantum neural network circuit. On a truncated MNIST dataset of 600 samples, a 4-qumode hybrid classifier achieves 100% training accuracy.
基金Engineering and Physical Sciences Research Council(project EP/T001011/1)Shenzhen-Hong Kong Cooperation Zone for Technology and Innovation(HZQB-KCZYB-2020050)+7 种基金Hong Kong Research Grant Council(R7035-21)Army Research Office(W911NF-23-1-0077)Multidisciplinary University Research Initiative(W911NF-21-1-0325)Air Force Office of Scientific Research(FA9550-19-1-0399,FA9550-21-1-0209)National Science Foundation(OMA-1936118,ERC-1941583,OMA-2137642)NTT ResearchDavid and Lucile Packard Foundation(2020-71479)Marshall and Arlene Bennett Family Research Program。
文摘Continuous-variable quantum key distribution(CV QKD)using optical coherent detectors is practically favorable due to its low implementation cost,flexibility of wavelength division multiplexing,and compatibility with standard coherent communication technologies.However,the security analysis and parameter estimation of CV QKD are complicated due to the infinite-dimensional latent Hilbert space.Also,the transmission of strong reference pulses undermines the security and complicates the experiments.In this work,we tackle these two problems by presenting a time-bin-encoding CV protocol with a simple phase-error-based security analysis valid under general coherent attacks.With the key encoded into the relative intensity between two optical modes,the need for global references is removed.Furthermore,phase randomization can be introduced to decouple the security analysis of different photon-number components.We can hence tag the photon number for each round,effectively estimate the associated privacy using a carefully designed coherent-detection method,and independently extract encryption keys from each component.Simulations manifest that the protocol using multi-photon components increases the key rate by two orders of magnitude compared to the one using only the single-photon component.Meanwhile,the protocol with four-intensity decoy analysis is sufficient to yield tight parameter estimation with a short-distance key-rate performance comparable to the best Bennett-Brassard-1984 implementation.
基金National Natural Science Foundation of China(62175138,62205188)Shanxi 1331KSCInnovation Program for Quantum Science and Technology(2021ZD0300703)。
文摘With the rapid spread of Internet technology,e-commerce is gradually becoming an integral part of the modern business models.The e-commerce transactions should obey integrity,authentication,nonrepudiation,traceability,and impartiality.Here,we propose and demonstrate a complete continuous-variable quantum e-commerce scheme,which involves subscription,payment,transport,and reception protocols among five parties.To this end,a simple,efficient quantum digital payment scheme is proposed.Furthermore,we streamline the entire e-commerce process by eliminating the private amplification step in the pre-distribution of keys.We achieve a contract signing rate of 1.51×10^(3)times per second for a 33 kilobits contract,and a payment rate of 2.70×10^(3)times per second over 80 km of single-mode fiber.Our results can support 411 times complete transactions per second,including three contract signings and two separate monetary payments.The proposed scheme takes into account the compatibility with existing e-commerce platforms to ensure a smooth transition and provides a practical solution for quantum e-commerce at metropolitan distances.
基金supported by the National Basic Research Program of China(Grant No.2010CB923103)the National Natural Science Foundation of China(Grant Nos.11322440,11074157,11174188 and 61121064)OIT and Shanxi Scholarship Council of China(Grant No.2012-010)
文摘The preparation of multipartite entangled states is the prerequisite for exploring quantum information networks and quantum computation.In this paper,we review the experimental progress in the preparation of cluster states and multi-color entangled states with continuous variables.The preparation of lager scale multipartite entangled state provide valuable quantum resources to implement more complex quantum informational tasks.
