多用户量子隐形传态网络分析

Analysis of Multi-user Quantum Teleportation Networks

量子隐形传态是量子信息处理技术中最重要的协议之一,最早的量子隐形传态发生在两用户之间。随着量子信息研究的深入发展,人们提出多用户量子隐形传态网络是未来量子互联网的基础。到目前为止,确定性量子隐形传态已经在三用户网络中得到了证明,多用途、确定性、涉及更多用户的量子隐形传态网络需要被进一步研究。本文提出利用四组份Greenberger-Horn-Zeilinger(GHZ)纠缠态光场来实现多用途量子隐形传态网络的构建方案,该方案可以实现不同用户的组合变换,根据组合形式不同,实现一个子网或者两个子网的多用途量子隐形传态网络。我们的方法灵活、可扩展,并将为复杂量子通信和量子计算协议的演示提供一个通用平台。

With the rapid development of quantum communication technology, quantum teleportation as an important quantum communication scheme has received widespread attention and has become one of the most important protocols in quantum information processing technology. The earliest quantum teleportation are natural two-partite processes for transferring unknown quantum states from one node to another. So far, deterministic quantum teleportation has been demonstrated in three-user networks, and as quantum information research progresses, quantum states or quantum information need to be transferred between more and more nodes.Therefore, multi-user quantum teleportation networks are considered to be the basis of the future quantum internet. However, a versatile and deterministic quantum teleportation network for different combinations of users is currently needed to meet the practical requirements, and thus the construction of continuously variable multi-user quantum teleportation networks is necessary.In this paper, we propose the construction of a multi-purpose quantum teleportation network using a four-partite GreenbergerHorn-Zeilinger(GHZ) entangled state of light, and the proposed four-partite quantum teleportation network can be constructed as a communication system containing one or two subnets. Users in this network can be flexibly associated as a subnetwork, and designated users can be selected to cooperate as needed, and different quantum teleportation networks are implemented under different cooperation methods, which realises the flexibility of network construction. Meanwhile, the physical conditions of implementing different networks are analysed in detail to provide a reference for obtaining high-fidelity and high-flexibility quantum teleportation networks.The results show that in order to ensure the efficient operation of the quantum teleportation network, it is necessary to have highquality entanglement resources, reasonable gain factors, a larger number of controllers, as well as efficient transmission and detection efficiency. With the advantages of flexibility and easy scalability, this scheme can be a useful reference for the realisation of more complex quantum computation and quantum communication networks in the future, using more components of entangled state optical fields, and will provide a general platform for the demonstration of complex quantum communication and quantum computation protocols.