State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China.
Sci Rep. 2017 Mar 15;7:44475. doi: 10.1038/srep44475.
A quantum communication network can be constructed by distributing a multipartite entangled state to space-separated nodes. Entangled optical beams with highest flying speed and measurable brightness can be used as carriers to convey information in quantum communication networks. Losses and noises existing in real communication channels will reduce or even totally destroy entanglement. The phenomenon of disentanglement will result in the complete failure of quantum communication. Here, we present the experimental demonstrations on the disentanglement and the entanglement revival of tripartite entangled optical beams used in a quantum network. We experimentally demonstrate that symmetric tripartite entangled optical beams are robust in pure lossy but noiseless channels. In a noisy channel, the excess noise will lead to the disentanglement and the destroyed entanglement can be revived by the use of a correlated noisy channel (non-Markovian environment). The presented results provide useful technical references for establishing quantum networks.
量子通信网络可以通过将多部分纠缠态分布到空间分离的节点来构建。具有最高飞行速度和可测量亮度的纠缠光束可用作载体，以在量子通信网络中传输信息。实际通信信道中存在的损耗和噪声会降低甚至完全破坏纠缠。去纠缠现象会导致量子通信完全失败。在这里，我们展示了用于量子网络的三方纠缠光的去纠缠和纠缠恢复的实验演示。我们的实验表明，对称三方纠缠光在纯损耗但无噪声的信道中是稳健的。在噪声信道中，额外噪声会导致去纠缠，而通过使用相关噪声信道（非马尔可夫环境）可以恢复已破坏的纠缠。所提出的结果为建立量子网络提供了有用的技术参考。
