Wen Yafei, Zhou Pai, Xu Zhongxiao, Yuan Liang, Wang Minjie, Wang Shengzhi, Chen Lirong, Wang Hai
Opt Express. 2020 Jan 6;28(1):360-368. doi: 10.1364/OE.376962.
The storage and retrieval efficiency (SRE) and lifetime of optical quantum memories are two key performance indicators for scaling up quantum information processing. Here, we experimentally demonstrate a cavity-enhanced long-lived optical memory for two polarizations in a cold atomic ensemble. Using electromagnetically induced-transparency (EIT) dynamics, we demonstrate the storages of left-circularly and right-circularly polarized signal light pulses in the atoms, respectively. By making the signal and control beams collinearly pass through the atoms and storing the two polarizations of the signal light as two magnetic-field-insensitive spin waves, we achieve a long-lived (3.5 ms) memory. By placing a low-finesse optical ring cavity around the cold atoms, the coupling between the signal light and the atoms is enhanced, which leads to an increase in SRE. The presented cavity-enhanced storage shows that the SRE is ∼30%, corresponding to an intrinsic SRE of ∼45%.
光量子存储器的存储与检索效率（SRE）以及寿命是扩大量子信息处理规模的两个关键性能指标。在此，我们通过实验展示了一种用于冷原子系综中两种偏振态的腔增强长寿命光存储器。利用电磁诱导透明（EIT）动力学，我们分别展示了左旋和右旋圆偏振信号光脉冲在原子中的存储。通过使信号光和控制光束共线穿过原子，并将信号光的两种偏振态存储为两个对磁场不敏感的自旋波，我们实现了长寿命（3.5毫秒）的存储器。通过在冷原子周围放置一个低精细度光学环形腔，增强了信号光与原子之间的耦合，这导致SRE增加。所展示的腔增强存储表明，SRE约为30%，对应的本征SRE约为45%。
