论文标题
检测量子信号上单个光子损失的事件
Detecting the event of a single photon loss on quantum signals
论文作者
论文摘要
我们设计了一个方案，用于检测通过纤维或自由空间传输的多模式量子信号的单个光子损失。这是由一种特殊类型的统一编码转换组成的，即受控平方，在信息和附属模式组成的信号上应用于传输之前。在接收器时，对统一转换进行了反向编码，并通过光子检测来测量Ancilla模式。结果表明是否发生了光子损失。如果选择了编码转换，则可以纠正由Ancilla光子损失引起的信号的信息部分的变形。从信号的信息部分中丢失光子，可以用指数近接近统一的概率检测到。与无抗性子空间和量子误差校正协议的方案相反，此方法允许人们使用整个希尔伯特空间维度。我们讨论综合所需编码解码转换的可能方法。
We design a scheme for detecting a single photon loss from multi-modal quantum signals transmitted via a fiber or in free space. This consists of a special type of unitary coding transformation, the controlled-squeezing, applied prior to the transmission on the signal composed by information and ancilla modes. At the receiver, the inverse unitary transformation is applied -decoding, and the ancilla modes are measured via photon detection. The outcome reveals whether a photon loss has occurred. Distortion of the information part of the signal caused by an ancilla photon loss can be corrected if the encoding transformation is appropriately selected. Loss of a photon from the information part of the signal can be detected with the probability exponentially close to unity. In contrast to the schemes of decoherence free subspaces and quantum error correction protocols, this methods allows one to make use of entire Hilbert space dimensionality. We discuss possible ways of synthesizing the required encoding-decoding transformations.
