Entanglement is a powerful tool for quantum sensing, and entangled states can greatly boost the discriminative power of protocols for quantum illumination, quantum metrology, or quantum reading. However, entangled state protocols generally require the retention of an idler state, to which the probes are entangled. Storing a quantum state is difficult and so technological limitations can make protocols requiring quantum memories impracticable. One alternative is idler-free protocols that utilize nonclassical sources but do not require any idler states to be stored. Here we apply such a protocol to the task of channel position finding. This involves finding a target channel in a sequence of background channels, and has many applications, including quantum sensing, quantum spectroscopy, and quantum reading.

中文翻译：

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无惰轮频道定位

纠缠是用于量子感测的强大工具，纠缠态可以极大地提高量子照明，量子计量或量子读取协议的判别能力。但是，纠缠状态协议通常需要保留探针纠缠到的空闲状态。存储量子状态很困难，因此技术限制会使要求量子存储器的协议不可行。一种选择是无闲置协议，该协议利用非经典资源，但不需要存储任何闲置状态。在这里，我们将这样的协议应用于信道位置查找的任务。这涉及在一系列背景通道中找到目标通道，并具有许多应用，包括量子感测，量子光谱学和量子读取。