论文标题
$^{40} $ ca $^+$ singles量子量子内存的电信量子光子接口
Telecom Quantum Photonic Interface for a $^{40}$Ca$^+$ Single-Ion Quantum Memory
论文作者
论文摘要
基于纠缠的量子网络需要固定量子记忆和光子之间的量子光子接口，从而实现纠缠分布。在这里，我们提出了这样的光子接口，旨在将$^{40} $ CA $^+$单离子量子内存连接到电信C波段。该界面结合了一种内存谐振，空腔增强的自发参数下调（SPDC）光子对源与双向极化量子量子转换（QFC）。我们证明了在转换过程中保存高保真纠缠，纤维的传输量高达40 km，并反转到记忆波长。即使在最长的距离和双向转换中，纠缠忠诚度仍然大于95％（98％），而没有（带有）背景校正。
Entanglement-based quantum networks require quantum photonic interfaces between stationary quantum memories and photons, enabling entanglement distribution. Here we present such a photonic interface, designed for connecting a $^{40}$Ca$^+$ single-ion quantum memory to the telecom C-band. The interface combines a memory-resonant, cavity-enhanced spontaneous parametric down-conversion (SPDC) photon pair source with bi-directional polarization-conserving quantum frequency conversion (QFC). We demonstrate preservation of high-fidelity entanglement during conversion, fiber transmission over up to 40 km and back-conversion to the memory wavelength. Even for the longest distance and bi-directional conversion the entanglement fidelity remains larger than 95 % (98 %) without (with) background correction.
