Yu Zhifei, Wu Zeliang, Li Xuejie, Feng Xiaotian, Huang Wenfeng, Zhang Keye, Yuan Chun-Hua, Zhang Weiping, Chen L Q
State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200062, China.
School of Physics and Astronomy, and Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China.
Phys Rev Lett. 2023 Oct 13;131(15):150804. doi: 10.1103/PhysRevLett.131.150804.
A quantum memory with the performances of low noise, high efficiency, and high bandwidth is of crucial importance for developing practical quantum information technologies. However, the excess noises generated during the highly efficient processing of quantum information inevitably destroy quantum state. Here, we present a quantum memory with built-in excess-noise eraser by integrating a photon-correlated quantum interferometry in quantum memory, where the memory efficiency can be enhanced and the excess noises can be suppressed to the vacuum level via destructive interference. This quantum memory is demonstrated in a rubidium vapor cell with a 10-ns-long photonics signal. We observe ∼80% noise suppression, the write-in efficiency enhancement from 87% to 96.2% without and with interferometry, and the corresponding memory efficiency excluding the noises from 70% to 77%. The fidelity is 93.7% at the single-photon level, significantly exceeding the no-cloning limit. Such interferometry-integrated quantum memory, the first expansion of quantum interference techniques to quantum information processing, simultaneously enables low noise, high bandwidth, high efficiency, and easy operation.
对于开发实用的量子信息技术而言，具备低噪声、高效率和高带宽性能的量子存储器至关重要。然而，在高效处理量子信息过程中产生的过量噪声不可避免地会破坏量子态。在此，我们通过将光子关联量子干涉测量法集成到量子存储器中，展示了一种内置过量噪声消除器的量子存储器，其中，通过相消干涉可提高存储效率并将过量噪声抑制到真空水平。这种量子存储器在一个铷蒸汽室中得到了验证，该蒸汽室使用了一个10纳秒长的光子信号。我们观察到约80%的噪声抑制，在未使用干涉测量法和使用干涉测量法时，写入效率分别从87%提高到96.2%，相应的排除噪声后的存储效率从70%提高到77%。在单光子水平下，保真度为93.7%，显著超过了不可克隆极限。这种集成干涉测量法的量子存储器是量子干涉技术首次向量子信息处理领域的扩展，同时实现了低噪声、高带宽、高效率和易于操作。
