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arXiv 1404.3733quant-phcs.CCcs.ITmath.IT
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量子信息复杂性与分摊通信

Quantum Information Complexity and Amortized Communication

Dave Touchette

摘要:

我们定义了量子协议的信息代价和相应的二分量子信道的量子信息复杂度,并研究了这些量的性质.这些是最近发现了许多应用的二分经典函数的类似量的完全量子推广,特别是用于证明通信复杂性下界。我们的定义与量子态再分配任务密切相关。以前的尝试已经为量子协议定义了这样一个量,考虑到特定的应用;我们的概念在许多方面与这些不同。首先,它直接提供了量子通信成本的下限,与底层协议的轮数无关。其次,我们对量子信息复杂度给出了一个操作解释:我们证明了它完全等于给定状态下二分信道的分摊量子通信复杂度。这将Braverman和Rao的一个结果推广到了量子协议,甚至加强了经典结果在有界圆形场景中的作用。此外,这为交互式量子协议提供了Schumacher源压缩定理的模拟,并回答了Braverman提出的问题。我们还讨论了一些潜在的应用,量子通信复杂性的下限,专门为经典函数和输入的定义。在Jain、Radhakrishnan和Sen工作的基础上,我们提供了新的证据,表明对于M-消息协议,不相交函数的有界圆量子通信复杂度是Ω(n/M + M)。这将与最著名的上限相匹配。

英文摘要:

We define a new notion of information cost for quantum protocols, and a corresponding notion of quantum information complexity for bipartite quantum channels, and then investigate the properties of such quantities. These are the fully quantum generalizations of the analogous quantities for bipartite classical functions that have found many applications recently, in particular for proving communication complexity lower bounds. Our definition is strongly tied to the quantum state redistribution task. Previous attempts have been made to define such a quantity for quantum protocols, with particular applications in mind; our notion differs from these in many respects. First, it directly provides a lower bound on the quantum communication cost, independent of the number of rounds of the underlying protocol. Secondly, we provide an operational interpretation for quantum information complexity: we show that it is exactly equal to the amortized quantum communication complexity of a bipartite channel on a given state. This generalizes a result of Braverman and Rao to quantum protocols, and even strengthens the classical result in a bounded round scenario. Also, this provides an analogue of the Schumacher source compression theorem for interactive quantum protocols, and answers a question raised by Braverman. We also discuss some potential applications to quantum communication complexity lower bounds by specializing our definition for classical functions and inputs. Building on work of Jain, Radhakrishnan and Sen, we provide new evidence suggesting that the bounded round quantum communication complexity of the disjointness function is Ω(n/M + M), for M-message protocols. This would match the best known upper bound.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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