We study the degree to which quantum entanglement survives when a three-qubit entangled state iscopied by using local and non-local processes, respectively, and investigate iterating quantum copyingfor the three-qubit...We study the degree to which quantum entanglement survives when a three-qubit entangled state iscopied by using local and non-local processes, respectively, and investigate iterating quantum copyingfor the three-qubitsystem. There may exist inter-three-qubit entanglement and inter-two-qubit entanglement for the three-qubit system.We show that both local and non-local copying processes degrade quantum entanglement in the three-particle systemdue to a residual correlation between the copied output and the copying machine. We also show that the inter-two-qubitentanglement is preserved better than the inter-three-qubit entanglement in the local cloning process. We find thatnon-local cloning is much more efficient than the local copying for broadcasting entanglement, and output state vianon-local cloning exhibits the fidelity better than local cloning.展开更多
Generating entangled states efficiently is a hot topic in the area of quantum information science.With the approach presented in this paper,a general parity gate could be realized and a wide range of entangled states,...Generating entangled states efficiently is a hot topic in the area of quantum information science.With the approach presented in this paper,a general parity gate could be realized and a wide range of entangled states,including GHZ state,W state,Dicke state,arbitrary graph state and locally maximally entanglable states,can be generated flexibly.The generation of GHZ state,W state,and Dicke state is probabilistic but heralded and the total success probability is unit.In addition,the arbitrary graph state and locally maximally entanglable states generation is deterministic,flexible,and highly efficient.Especially,with the"simultaneous"generation pattern,the complexity of the graph state generation and locally maximally entanglable states generation could be reduced greatly,providing a more efficient and feasible way to generate the entangled states.展开更多
基金the National Fundamental Research Program，国家自然科学基金，教育部EYTF项目，湖南省科研项目
文摘We study the degree to which quantum entanglement survives when a three-qubit entangled state iscopied by using local and non-local processes, respectively, and investigate iterating quantum copyingfor the three-qubitsystem. There may exist inter-three-qubit entanglement and inter-two-qubit entanglement for the three-qubit system.We show that both local and non-local copying processes degrade quantum entanglement in the three-particle systemdue to a residual correlation between the copied output and the copying machine. We also show that the inter-two-qubitentanglement is preserved better than the inter-three-qubit entanglement in the local cloning process. We find thatnon-local cloning is much more efficient than the local copying for broadcasting entanglement, and output state vianon-local cloning exhibits the fidelity better than local cloning.
基金supported by the National Natural Science Foundation of China(Grant No.11005040)the Program for New Century Excellent Talents in Fujian Province University(Grant No.2012FJ-NCET-ZR04)+1 种基金the Natural Science Foundation of Fujian Province of China(Grant No.2014J01015)the Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University(Grant No.ZQN-PY113)
文摘Generating entangled states efficiently is a hot topic in the area of quantum information science.With the approach presented in this paper,a general parity gate could be realized and a wide range of entangled states,including GHZ state,W state,Dicke state,arbitrary graph state and locally maximally entanglable states,can be generated flexibly.The generation of GHZ state,W state,and Dicke state is probabilistic but heralded and the total success probability is unit.In addition,the arbitrary graph state and locally maximally entanglable states generation is deterministic,flexible,and highly efficient.Especially,with the"simultaneous"generation pattern,the complexity of the graph state generation and locally maximally entanglable states generation could be reduced greatly,providing a more efficient and feasible way to generate the entangled states.
