Cooperative communication is starting to attract substantial research attention in quantum information theory. However, given a specific network, it is still unknown whether quantum cooperative communication can be su...
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Cooperative communication is starting to attract substantial research attention in quantum information theory. However, given a specific network, it is still unknown whether quantum cooperative communication can be successfully performed. In this paper, we investigate networkcoding for quantum cooperative multicast (QCM) over the classic butterfly network. A very reasonable definition of QCM is first introduced. It not only perfectly focuses on the basic idea of quantum cooperative communication, but also wonderfully reflects the characteristic of classical multicast over a specific network structure. Next, we design QCM protocol for two-level systems and generalize the protocol into d-dimensional Hilbert space. It is shown that our protocols have significant advantages in terms of resource cost and compatibility with classical multicast. Besides, the success probability, which only depends on the coefficients of the initial quantum states, is carefully analyzed. In particular if the source nodes choose the quantum equatorial states, success probability can reach 1.
We study the problem of quantum multi-unicast communication over the butterfly network in a quantum-walk architecture, where multiple arbitrary single-qubit states are transmitted simultaneously between multiple sourc...
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We study the problem of quantum multi-unicast communication over the butterfly network in a quantum-walk architecture, where multiple arbitrary single-qubit states are transmitted simultaneously between multiple source-sink pairs. Here, by introducing quantum walks, we demonstrate a quantum multiunicast communication scheme over the butterfly network and the inverted crown network, respectively,where the arbitrary single-qubit states can be efficiently transferred with both the probability and the state fidelity one. The presented result concerns only the butterfly network and the inverted crown network, but our techniques can be applied to a more general graph. It paves a way to combine quantum computation and quantumnetwork communication.
Following some ideas of the quantum network coding protocol [Phys. Rev. A 76 (2007) 040301], we propose an efficient protocol to transmit two 2-level quantum states crossly over the butterfly network with two non-maxi...
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Following some ideas of the quantum network coding protocol [Phys. Rev. A 76 (2007) 040301], we propose an efficient protocol to transmit two 2-level quantum states crossly over the butterfly network with two non-maximally entangled qubit pairs shared only between two senders. It is shown that both of the receivers can reestablish the initial states with a certain probability. And one classical bit communication can be saved at the bottleneck channel. Moreover, this protocol is generalized to the case of transmitting two multipartite entangled states. (C) 2009 Elsevier B.V. All rights reserved.
A novel determinate joint remote preparation scheme of an arbitrary W-class quantum state is proposed to improve the probability of successful preparation. The presented scheme is realized through orthogonal projectiv...
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A novel determinate joint remote preparation scheme of an arbitrary W-class quantum state is proposed to improve the probability of successful preparation. The presented scheme is realized through orthogonal projective measurement of the Hadamard transferred basis, which converts a global measurement to several local measurements. Thus orthogonal projective measurement of the Hadamard transferred basis enables quantum information to be transmitted from different sources simultaneously, which is a breakthrough for quantumnetwork node processing. Finally, analysis shows the feasibility and validity of the proposed method, with a 100% probability of successful preparation.
We propose a deterministic and faithful scheme for realizing the assisted clone of an unknown two-particle entangled state. The first stage of the protocol requires teleportation via maximal entanglement. In the secon...
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We propose a deterministic and faithful scheme for realizing the assisted clone of an unknown two-particle entangled state. The first stage of the protocol requires teleportation via maximal entanglement. In the second stage, a novel set of mutually orthogonal basis vectors is constructed. With the assistance of the preparer through a two-particle projective measurement under this basis, a perfect copy of an original state can be produced. Compared with the previous protocols which produce the unknown state and its orthogonal complement state at the site of the sender, our scheme generates the unknown state deterministically. On the other hand, we put forward another assisted clone scheme via nonmaximal entanglement as the quantum channel. A faithful copy of the unknown state can be obtained with a certain probability.
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