发表机构
Nara Institute of Science and Technology; University of Calgary; University of Hong Kong（奈良先端科学技术大学院大学; 卡尔加里大学; 香港大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种基于相干态和阈值探测器、结合线性回归诱饵态后处理的方法，以模拟单光子源和PNR探测器，显著提升精度并减少探针资源，适用于酉及非酉量子信道，可支持多种量子信息处理应用。
AI 中文摘要
光子量子比特在量子信息处理中扮演着重要角色。然而，迄今为止，高效高速的单光子源和光子数分辨（PNR）探测器仍然难以制造。在此，我们使用相位随机化相干态和阈值探测器，结合诱饵态后处理，来模拟单光子源和PNR探测器，并执行各种量子信息处理任务。我们提出了一种简单的线性回归方法，基于相干态探针的可观测统计量来预测Fock态统计量，并结合探针设置的随机/结构化采样。与基于线性规划和笛卡尔积网格采样的传统诱饵态后处理相比，我们的方法能够显著提高精度并大幅减少探针资源。它对于具有固定尺寸希尔伯特空间维度的未知酉电路尤其有效。例如，它仅需32个输入/输出探针设置即可精确模拟线性光学中的4光子干涉，以及仅需256个探针设置即可模拟6光子干涉。此外，它同样适用于非酉（例如有损、非线性或任意）量子信道。这使得各种应用得以实现，这些应用可以使用易于获得的相干光源和阈值探测器来实施，例如小规模线性光学量子计算电路的表征或量子传感/计量设备的表征。
英文摘要
Photonic qubits play an important role in quantum information processing. However, to date, efficient high-speed single photon sources and photon number resolving (PNR) detectors are still difficult to make. Here, we use phase-randomized coherent states and threshold detectors, combined with decoy-state post-processing, to simulate single photon sources and PNR detectors and perform various quantum information processing tasks. We propose a simple linear regression method to predict Fock state statistics based on observable statistics from coherent-state probes, combined with random/structured sampling of probe settings. Compared with traditional decoy-state post-processing based on linear programming and Cartesian product grid sampling, our method enables drastically improved accuracy and much reduced probe resources. It works particularly well for unknown unitary circuits of interest with fixed-size Hilbert space dimensions. For instance, it can accurately simulate 4-photon interference in linear optics with just 32 input/output probe settings and 6-photon interference with 256 probe settings. Moreover, it also works for non-unitary (such as lossy, nonlinear, or arbitrary) quantum channels. This enables a wide variety of applications that can be implemented with easily attainable coherent light sources and threshold detectors, such as characterization of small-scale linear optical quantum computing circuits or quantum sensing/metrology devices.
