论文标题
使用光谱量子干扰的非局部亚秒延迟计量
Nonlocal subpicosecond delay metrology using spectral quantum interference
论文作者
论文摘要
时间和定位测量是基本量子网络操作（例如贝尔状态测量）的关键要求。使用单光子检测器的常规飞行时间测量通常受到检测正时抖动的限制。在这项工作中，我们通过使用宽带时间能量纠缠的光子的紧密时序相关性来衡量具有子秒分辨率的相对链接潜伏期的变化的非本地方案。我们的感应方案依赖于通过相调制实现的光谱干扰，然后进行过滤和双光子重合测量，并且具有弹性，可抵御双光线遍历的光学链接之间的微秒尺度不匹配。我们的实验证明了在非局部延迟变化的测量和+/- 0.7°的测量射频相变的测量中的精度为+/- 0.04 ps。此外，我们通过同一设置中的单光子检测器的时间标签信息补充了我们的技术，以呈现延迟变化的明确感知。该技术可以使用现成的电信设备实施，从而使其适应实用的量子网络基础架构。
Timing and positioning measurements are key requisites for essential quantum network operations such as Bell state measurement. Conventional time-of-flight measurements using single-photon detectors are often limited by detection timing jitter. In this work, we demonstrate a nonlocal scheme to measure changes in relative link latencies with subpicosecond resolution by using tight timing correlation of broadband time-energy entangled photons. Our sensing scheme relies on spectral interference achieved via phase modulation, followed by filtering and biphoton coincidence measurements, and is resilient to microsecond-scale mismatch between the optical link traversed by the biphotons. Our experiments demonstrate a precision of +/-0.04 ps in measurements of nonlocal delay changes and +/-0.7° in measurements of radio-frequency phase changes. Furthermore, we complement our technique with time-tag information from single-photon detectors in the same setup to present unambiguous sensing of delay changes. The proposed technique can be implemented using off-the-shelf telecom equipment thus rendering it adaptable to practical quantum network infrastructure.
