论文标题
不可能创建未知量子状态的叠加
Impossibility of creating a superposition of unknown quantum states
论文作者
论文摘要
叠加原则是量子理论的基础。然而，最近的一个无关定理证明，即使没有零概率，量子理论也禁止对未知量子状态的叠加。然而，到目前为止，这种结果的含义仍然很糟糕。在本文中，我们表明，具有两个未知纯状态的协议的存在，具有非零概率（允许超出输入状态）会导致违反其他无关定理。特别是，这种协议可用于执行某些状态歧视和克隆任务，这些任务不仅在量子理论中被禁止，而且在无信号理论中被禁止。
The superposition principle is fundamental to quantum theory. Yet a recent no-go theorem has proved that quantum theory forbids superposition of unknown quantum states, even with nonzero probability. The implications of this result, however, remain poorly understood so far. In this paper we show that the existence of a protocol that superposes two unknown pure states with nonzero probability (allowed to vary over input states) leads to violation of other no-go theorems. In particular, such a protocol can be used to perform certain state discrimination and cloning tasks that are forbidden not only in quantum theory but in no-signaling theories as well.
