Zhang Wei, Ding Dong-Sheng, Sheng Yu-Bo, Zhou Lan, Shi Bao-Sen, Guo Guang-Can
Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Phys Rev Lett. 2017 Jun 2;118(22):220501. doi: 10.1103/PhysRevLett.118.220501. Epub 2017 May 31.
Quantum communication provides an absolute security advantage, and it has been widely developed over the past 30 years. As an important branch of quantum communication, quantum secure direct communication (QSDC) promotes high security and instantaneousness in communication through directly transmitting messages over a quantum channel. The full implementation of a quantum protocol always requires the ability to control the transfer of a message effectively in the time domain; thus, it is essential to combine QSDC with quantum memory to accomplish the communication task. In this Letter, we report the experimental demonstration of QSDC with state-of-the-art atomic quantum memory for the first time in principle. We use the polarization degrees of freedom of photons as the information carrier, and the fidelity of entanglement decoding is verified as approximately 90%. Our work completes a fundamental step toward practical QSDC and demonstrates a potential application for long-distance quantum communication in a quantum network.
量子通信具有绝对的安全优势，在过去30年里得到了广泛发展。作为量子通信的一个重要分支，量子安全直接通信（QSDC）通过在量子信道上直接传输消息，提升了通信的高安全性和即时性。量子协议的全面实现始终需要在时域中有效控制消息传输的能力；因此，将QSDC与量子存储器相结合以完成通信任务至关重要。在本信函中，我们首次原则上报告了利用最先进的原子量子存储器进行QSDC的实验演示。我们将光子的偏振自由度用作信息载体，并且验证了纠缠解码的保真度约为90%。我们的工作朝着实用的QSDC迈出了重要一步，并展示了在量子网络中进行长距离量子通信的潜在应用。
