Ma Lixia, Lei Xing, Yan Jieli, Li Ruiyang, Chai Ting, Yan Zhihui, Jia Xiaojun, Xie Changde, Peng Kunchi
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, P. R. China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, P. R. China.
Nat Commun. 2022 May 2;13(1):2368. doi: 10.1038/s41467-022-30077-1.
High-performance quantum memory for quantized states of light is a prerequisite building block of quantum information technology. Despite great progresses of optical quantum memories based on interactions of light and atoms, physical features of these memories still cannot satisfy requirements for applications in practical quantum information systems, since all of them suffer from trade-off between memory efficiency and excess noise. Here, we report a high-performance cavity-enhanced electromagnetically-induced-transparency memory with warm atomic cell in which a scheme of optimizing the spatial and temporal modes based on the time-reversal approach is applied. The memory efficiency up to 67 ± 1% is directly measured and a noise level close to quantum noise limit is simultaneously reached. It has been experimentally demonstrated that the average fidelities for a set of input coherent states with different phases and amplitudes within a Gaussian distribution have exceeded the classical benchmark fidelities. Thus the realized quantum memory platform has been capable of preserving quantized optical states, and is ready to be applied in quantum information systems, such as distributed quantum logic gates and quantum-enhanced atomic magnetometry.
用于光量子化态的高性能量子存储器是量子信息技术的一个先决构建模块。尽管基于光与原子相互作用的光量子存储器取得了巨大进展，但这些存储器的物理特性仍无法满足实际量子信息系统应用的要求，因为它们都在存储效率和过量噪声之间存在权衡。在此，我们报道了一种具有热原子单元的高性能腔增强电磁诱导透明存储器，其中应用了基于时间反演方法优化空间和时间模式的方案。直接测量到高达67±1%的存储效率，同时达到了接近量子噪声极限的噪声水平。实验证明，高斯分布内一组具有不同相位和幅度的输入相干态的平均保真度超过了经典基准保真度。因此，所实现的量子存储器平台能够保存量子化光态，并准备应用于量子信息系统，如分布式量子逻辑门和量子增强原子磁力测量。
