北京散射与辐射国家重点实验室QuanChun Yu团队利用零光子减法提升了量子雷达性能。该成果于2025年2月24日发表于《物理评论A》杂志。

量子雷达，也称为量子照明，是一种用于检测隐藏在噪声环境中的非合作目标的量子传感协议。最近，大量的研究工作集中在通过条件光子探测方法优化量子照明上，如纠缠源的光子减法和光子催化。然而，迄今为止，这些研究几乎都没有考虑过成功探测非零光子的可能性。通常，条件非零光子探测的概率极低，这可能会抵消量子雷达中条件测量的优势。

在此，研究组提出使用零光子减法（ZPS）来提高量子雷达的性能，其中没有从给定的光学系统中减去物理光子。他们证明ZPS的概率比非零光子探测的概率高一到两个数量级。研究结果表明，即使考虑到光子探测的概率，ZPS也有助于提高量子雷达的性能。

此外，研究组考虑了一种更现实的量子雷达，其中使用振幅阻尼量子纠缠进行目标检测，这在雷达发射机中更常用于量子纠缠的制备。这意味着ZPS是一种更有效的量子照明条件光子探测方法，为开发未来的量子雷达提供了一种更稳健的方案。

附：英文原文

Title: Enhancing the performance of quantum radar with zero-photon subtraction

Author: ShengLi Zhang, Liangsheng Li, Maoxin Liu, JinChun Li, Wang Sun, QuanChun Yu

Issue&Volume: 2025/02/24

Abstract: Quantum radar, also known as quantum illumination, is a type of quantum-sensing protocol for detecting noncooperative targets hidden in noisy environments. Recently, considerable research efforts have been focused on optimizing quantum illumination via conditional photon-detection methods, such as photon subtraction and photon catalysis of the entanglement source. However, to date, almost none of these studies have considered the probability of successful detection of nonzero photons. Often, the probability of conditional nonzero photon detection is extremely low, which may negate the advantage of conditional measurements in a quantum radar. In this paper, we propose enhancing the performance of quantum radars using zero-photon subtraction (ZPS), where no physical photons are subtracted from a given optical system. We demonstrate that the probability of ZPS is one or two orders of magnitude higher than that of nonzero photon detection. Our results show that ZPS helps enhance the performance of quantum radars, even when the probability of photon detection is considered. Moreover, in this paper, we consider a more realistic quantum radar in which target detection is performed using amplitude-damped quantum entanglement, which is more commonly used in the preparation of quantum entanglement in radar transmitters. This means that ZPS is a more efficient conditional photon-detection method for quantum illumination, providing a more robust scheme for developing future quantum radars.

DOI: 10.1103/PhysRevA.111.022627

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.022627