One-Shot Decoupling
One-Shot Decoupling
复制标题
DOI：
10.1007/s00220-014-1990-4
复制
发表时间：
2014-05-01
影响因子：
2.4
通讯作者：
Renner, Renato
中科院分区：
文献类型：
--
作者：
Dupuis, Frederic;Berta, Mario;Renner, Renato
如果一个最初与另一个系统E相关的量子系统A经历了与E分离的演化，那么与E的相关性通常会降低。在这里，我们研究相关性（几乎）完全消失的条件，导致A与E解耦。我们给出了一个解耦的标准，在两个光滑熵，一个量化的数量A和E之间的初始相关性，和其他特征的映射，描述了A的演变。该准则适用于一般单次设置中的任意映射。此外，该准则对于满足一定自然条件的映射是紧的。单次解耦在物理学和信息论中都有许多应用，例如，作为量子信息处理协议的基础。作为一个例子，我们给出了一个一次性的状态合并协议，并表明它是本质上最优的纠缠消耗/生产。
If a quantum system A, which is initially correlated to another system, E, undergoes an evolution separated from E, then the correlation to E generally decreases. Here, we study the conditions under which the correlation disappears (almost) completely, resulting in a decoupling of A from E. We give a criterion for decoupling in terms of two smooth entropies, one quantifying the amount of initial correlation between A and E, and the other characterizing the mapping that describes the evolution of A. The criterion applies to arbitrary such mappings in the general one-shot setting. Furthermore, the criterion is tight for mappings that satisfy certain natural conditions. One-shot decoupling has a number of applications both in physics and information theory, e.g., as a building block for quantum information processing protocols. As an example, we give a one-shot state merging protocol and show that it is essentially optimal in terms of its entanglement consumption/production.