Quantum and classical message protect identification via quantum channels
Quantum and classical message protect identification via quantum channels
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量子和经典消息通过量子通道保护身份识别
DOI：
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发表时间：
2004
影响因子：
1
通讯作者：
A. Winter
中科院分区：
文献类型：
--
作者：
A. Winter
我们讨论了Ahlswede和Dueckvia一般量子信道的意义上的信息识别的概念，扩展经典信道的调查，初始工作forclassical-量子（CQ）信道和“量子指纹”。我们表明，离散无记忆量子通道对经典信息的识别能力可以大于传输能力;这与之前考虑的所有模型相反，其中它等于公共随机能力（在我们的情况下等于传输能力）：特别是，对于无噪声量子比特，我们表明识别能力为2，而传输和公共随机能力为1。然后我们转向量子信息识别的自然概念（即量子态的“指纹”概念）。这更接近量子信息传输，而不是经典的量子信息传输（首先，与经典识别的双指数相比，代码长度只呈指数增长）。事实上，我们展示了这个问题如何与可见量子编码有很好的联系。令人惊讶的是，对于无噪声的量子比特通道，这个容量是2：换句话说，可以将两个量子比特压缩成一个，这是最佳的。然而，在一般情况下，我们推测quantumidentification能力是从经典的识别能力不同。
We discuss concepts of message identification in the sense of Ahlswede and Dueckvia general quantum channels, extending investigations for classical channels, initial work forclassical--quantum (cq) channels and "quantum fingerprinting". We show that the identificationcapacity of a discrete memoryless quantum channel for classical informationcan be larger than that for transmission; this is in contrast to all previously consideredmodels, where it turns out to equal the common randomness capacity (equals transmissioncapacity in our case): in particular, for a noiseless qubit, we show the identificationcapacity to be 2, while transmission and common randomness capacity are 1. Then weturn to a natural concept of identification of quantum messages (i.e. a notion of "fingerprint"for quantum states). This is much closer to quantum information transmissionthan its classical counterpart (for one thing, the code length grows only exponentially,compared to double exponentially for classical identification). Indeed, we show how theproblem exhibits a nice connection to visible quantum coding. Astonishingly, for thenoiseless qubit channel this capacity turns out to be 2: in other words, one can compress twoqubits into one and this is optimal. In general however, we conjecture quantumidentification capacity to be different from classical identification capacity.