A universal entangler is a very powerful fault-tolerant entangling device for generating quantum entanglements from any joint states. Our paper aims to address the construction of universal entanglers. We prove that u...A universal entangler is a very powerful fault-tolerant entangling device for generating quantum entanglements from any joint states. Our paper aims to address the construction of universal entanglers. We prove that universal entanglers may be obtained from random unitary gates according to the Harr measure. The success probability is close to 1 for large system spaces. This result represents the typical density of entanglement subspaces in large state spaces. It also partially solves an open problem of universal bipartite entanglers and is explained by some experiment simulations.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61303039,61272514,61003287,61170272,61121061 and 61161140320)the Fundamental Research Funds for the Central Universities(Grant No.2682014CX095)+3 种基金New Century Excellent Talents in University(Grant No.NCET-13-0681)the National Development Foundation-for Cryptological Research(Grant No.MMJJ201401012)the Fok Ying Tong Education Foundation(Grant No.131067)the Science Foundation Ireland under the International Strategic Cooperation Award(Grant No.SFI/12/ISCA/2496)
文摘A universal entangler is a very powerful fault-tolerant entangling device for generating quantum entanglements from any joint states. Our paper aims to address the construction of universal entanglers. We prove that universal entanglers may be obtained from random unitary gates according to the Harr measure. The success probability is close to 1 for large system spaces. This result represents the typical density of entanglement subspaces in large state spaces. It also partially solves an open problem of universal bipartite entanglers and is explained by some experiment simulations.