实现高效率、高保真度且长寿命的单光子量子态存储，对于实现量子中继和量子网络有着重要的意义。目前，虽然单光子存储的存储效率已经获得突破性进展，但是其存储时间依然有待提高。本项目计划基于电磁诱导透明技术，在保证单光子存储效率的同时，将其存储时间提高到毫秒量级。项目具体的研究内容为：1.在超高真空系统中实现光学厚度大于500的冷原子系综的制备；2.基于冷原子系综以及电磁诱导透明效应实现效率高于90%、寿命达到毫秒量级的单光子存储；3.基于冷原子系综以及电磁诱导透明效应实现效率高于85%、保真度高于99%的偏振比特存储，并使存储寿命达到毫秒量级。本项目将为量子中继和量子网络的研究提供支撑。

The realization of high efficiency and high fidelity long-lifetime quantum memory of single photon is of great significance for the realization of quantum repeater and quantum network. At present, although the storage efficiency of single photon storage has made a breakthrough, its storage lifetime still needs to be improved. Based on the electromagnetically induced transparency technology, this project plans to improve the storage time of single photon to millisecond while ensuring the storage efficiency. This project contents: 1. The preparation of cold atomic ensemble with optical depth over 500 in ultra-high vacuum system; 2. High efficiency (>90%) and long-lifetime(>ms) single photon storage based on cold atomic ensemble and electromagnetically induced transparency effect; 3. High efficiency (>85%) and high fidelity (>99%) long-lifetime (>ms) polarization qubit storage based on cold atom ensemble and electromagnetically induced transparency effect. This project will provide a support for the research of quantum repeater and quantum network.