论文标题
局部测量的不兼容为局部量子状态歧视提供了优势
Incompatibility of local measurements provide advantage in local quantum state discrimination
论文作者
论文摘要
不确定性原理可以被认为是引起观察到的不相容性的概念。一包不能同时测量的量子测量值据说形成了一组不相容的测量值。在量子状态歧视任务中,每组不兼容的测量值都比兼容的测量值都有优势,在量子状态歧视任务中,一个人从合奏中准备状态并将其发送给另一方,后者试图使用可用的测量结果来检测状态。已知全球和局部量子状态歧视之间的比较会导致“非局部性”现象。在这项工作中,我们密封了局部量子状态歧视和不兼容量子测量的域之间的联系。我们考虑局部量子状态歧视任务,其中发件人准备双方状态并将子系统发送给两个接收器。接收器尝试使用本地不兼容的测量来检测已发送的状态。我们分析了使用不兼容的测量结果成功猜测状态的概率的比率,以及使用兼容测量结果成功猜测状态的最大概率。我们发现,该比率是由局部测量不兼容的鲁棒性的简单函数的上限。有趣的是,与每组不兼容的测量值相对应,至少存在一项局部歧视任务,可以实现这种界限。我们认为,最佳的本地量子状态歧视任务没有显示任何“非局部性”,在该术语中,该术语是在比率之间的差异的意义上使用的,在全球和地方州歧视中通过不兼容和兼容测量成功检测的概率。结果可以推广到多分分局部量子状态区分任务的制度。
The uncertainty principle may be considered as giving rise to the notion of incompatibility of observables. A pack of quantum measurements that cannot be measured simultaneously is said to form a set of incompatible measurements. Every set of incompatible measurements has an advantage over the compatible ones in a quantum state discrimination task where one prepares a state from an ensemble and sends it to another party, and the latter tries to detect the state using available measurements. Comparison between global and local quantum state discriminations is known to lead to a phenomenon of "nonlocality". In this work, we seal a connection between the domains of local quantum state discrimination and incompatible quantum measurements. We consider the local quantum state discrimination task where a sender prepares a bipartite state and sends the subsystems to two receivers. The receivers try to detect the sent state using locally incompatible measurements. We analyze the ratio of the probability of successfully guessing the state using incompatible measurements and the maximum probability of successfully guessing the state using compatible measurements. We find that this ratio is upper bounded by a simple function of robustnesses of incompatibilities of the local measurements. Interestingly, corresponding to every pair of sets of incompatible measurements, there exists at least one local state discrimination task where this bound can be achieved. We argue that the optimal local quantum state discrimination task does not present any "nonlocality", where the term is used in the sense of a difference between the ratios, of probabilities of successful detection via incompatible and compatible measurements, in global and local state discriminations. The results can be generalized to the regime of multipartite local quantum state distinguishing tasks.