论文标题
目睹与单个量子粒子的潜在时间相关
Witnessing latent time correlations with a single quantum particle
论文作者
论文摘要
当多次使用嘈杂的通信通道时，在不同时间发生的误差通常会显示出相关性。从经典上讲，这些相关性不会影响单个粒子的演变：单个经典粒子只能在确定的时间时刻遍历通道，并且其演变对通道后续使用之间的相关性不敏感。与之形成鲜明对比的是，我们在这里表明，单个量子粒子可以在不同时间时刻感知通道多次用途之间的相关性。在一个极端的示例中，我们表明，当粒子在确定的时间发送时输出白噪声的通道可以表现出相关性，当粒子以两次叠加发送时，可以完美地传播经典位。相比之下，我们表明，由于缺乏相关性，以两次叠加发送的单个粒子会经过一个有效的通道，其经典能力最多为0.16位。当有多个传输线可用时，可以使用时间相关性来模拟量子通道在替代因果订单的连贯叠加中的应用，甚至提供通过因果订单的叠加无法获得的通信优势。
When a noisy communication channel is used multiple times, the errors occurring at different times generally exhibit correlations. Classically, these correlations do not affect the evolution of individual particles: a single classical particle can only traverse the channel at a definite moment of time, and its evolution is insensitive to the correlations between subsequent uses of the channel. In stark contrast, here we show that a single quantum particle can sense the correlations between multiple uses of a channel at different moments of time. In an extreme example, we show that a channel that outputs white noise when the particle is sent at a definite time can exhibit correlations that enable a perfect transmission of classical bits when the particle is sent at a superposition of two times. In contrast, we show that, in the lack of correlations, a single particle sent at a superposition of two times undergoes an effective channel with classical capacity of at most 0.16 bits. When multiple transmission lines are available, time correlations can be used to simulate the application of quantum channels in a coherent superposition of alternative causal orders, and even to provide communication advantages that are not accessible through the superposition of causal orders.
