论文标题
第一光子目标检测：击败Nair的纯损失性能限制
First-photon target detection: Beating Nair's pure-loss performance limit
论文作者
论文摘要
2011年，NAIR发表了无关定理用于量子雷达靶标检测[Phys。修订版A {\ bf 84}，032312（2011）]。他表明，在相当普遍的假设下，相干状态雷达的误差概率在纯损失（无背景辐射）通道的两个最佳量子性能之内，其圆形雷达雷达雷达雷达雷达雷达到触点到射线透射率$κ$满足$κ\ ll 1 $。我们介绍了第一光子雷达（FPRS），以绕过Nair的性能限制。 FPR会在每个变速器的返回的辐射上传递理想的直接检测（单位量子效率和无黑性计数）的理想直接检测（光子计数），从而传输了至少一个光子或预备的最大值$ m $脉冲。他们决定存在一个目标，并且仅当他们检测到一个或多个光子时。我们考虑量子（每个传输脉冲都是数字状态），并且经典（每个传输脉冲都是连贯的状态）FPR，我们表明当$κ\ ll 1 $ $时，它们的错误概率指数几乎相同。在其他假设是$κN_S\ ll 1 $的情况下，我们发现它们在NAIR性能限制上的优势将其优势增长到3 dB，为$ M \ rightarrow \ rightarrow \ infty $。但是，由于FPRS的脉冲重复期必须超过雷达到靶标传播的延迟，因此它们在对移动目标的对抗感知中的使用可能会采用$κN_S\ sim \ sim 1 $ 1 $和$ m \ sim 10 $，并实现〜2 db的优势。我们的工作构成了用于量子雷达目标检测的新的无定理。
In 2011, Nair published a no-go theorem for quantum radar target detection [Phys. Rev. A {\bf 84}, 032312 (2011)]. He showed, under fairly general assumptions, that a coherent-state radar's error probability was within a factor of two of the best possible quantum performance for the pure-loss (no background radiation) channel whose roundtrip radar-to-target-to-radar transmissivity $κ$ satisfies $κ\ll 1$. We introduce first-photon radars (FPRs) to circumvent and beat Nair's performance limit. FPRs transmit a periodic sequence of pulses, each containing $N_S$ photons on average, and perform ideal direct detection (photon counting at unit quantum efficiency and no dark counts) on the returned radiation from each transmission until at least one photon has been detected or a pre-set maximum of $M$ pulses has been transmitted. They decide a target is present if and only if they detect one or more photons. We consider both quantum (each transmitted pulse is a number state) and classical (each transmitted pulse is a coherent state) FPRs, and we show that their error-probability exponents are nearly identical when $κ\ll 1$. With the additional assumption that $κN_S \ll 1$, we find that their advantage in error-probability exponent over Nair's performance limit grows to 3 dB as $M \rightarrow \infty$. However, because FPRs' pulse-repetition period must exceed the radar-to-target-to-radar propagation delay, their use in standoff sensing of moving targets will likely employ $κN_S \sim 1$ and $M \sim 10$ and achieve ~2 dB advantage. Our work constitutes a new no-go theorem for quantum radar target detection.
