Unconstrained Summoning for relativistic quantum information processing

Efficient Code for Relativistic Quantum Summoning

Summoning retrieves quantum information, prepared somewhere in spacetime, at another specified point in spacetime, but this task is limited by the quantum no-cloning principle and the speed-of-light bound. We develop a thorough mathematical framework for summoning quantum information in a relativistic system and formulate a quantum summoning protocol for any valid configuration of causal diamonds in spacetime. For single-qubit summoning, we present a protocol based on a Calderbank-Shor-Steane code that decreases the space complexity for encoding by a factor of two compared to the previous best…

相对论量子理论中的一个无召唤定理

A No-summoning theorem in Relativistic Quantum Theory

在P的因果未来中的某个点Q，爱丽丝会向鲍勃要回这个状态。Bob知道这一点，但直到请求发出时才知道Q在哪一点。对于伽利略时空中的一个量子态或闵可夫斯基时空中的一个经典态，鲍勃可以满足爱丽丝的召唤，具有任意短的延迟。然而，由于闵可夫斯基时空中的一个未知的量子态，他通常不能满足她的召唤。这个{ \it无召唤定理}是相对论性量子理论的基本特征和内在特征。它遵循无信号原理和无克隆定理，但不是单独的。

Summoning, No-Signaling and Relativistic Bit Commitments

Summoning is a task between two parties, Alice and Bob, with distributed networks of agents in space-time. Bob gives Alice a random quantum state, known to him but not her, at some point. She is required to return the state at some later point, belonging to a subset defined by communications received from Bob at other points. Many results about summoning, including the impossibility of unrestricted summoning tasks and the necessary conditions for specific types of summoning tasks to be possible, follow directly from the quantum no-cloning theorem and the relativistic no-superluminal-signalling…

选择的量子粒子：更多的自由使召唤量子态更难

A Quantum Paradox of Choice: More Freedom Makes Summoning a Quantum State Harder

时空中量子信息的性质可以通过研究操作任务来研究。在一个这样的任务中，召唤，一个未知的量子态在一个点上被提供，在另一个点上发出一个调用，以便在第三个点上返回。Hayden-May最近证明了当保证最多一次召唤时，有限集合的召唤和返回点保证召唤状态成功返回的充分必要条件。我们证明了必要和充分条件时，可能有几个可能的选择和遵守任何一个构成成功。我们证明了在召唤中存在一个“选择的量子悖论”：完成任务的额外自由使它变得更加困难。这一有趣的结果在分布式量子计算和密码学中有实际应用，也对我们理解相对论性量子信息及其在时空中的局域化有意义。

S-money: virtual tokens for a relativistic economy

We propose definitions and implementations of "S-money" - virtual tokens designed for high value fast transactions on networks with relativistic or other trusted signalling constraints, defined by inputs that in general are made at many network points, some or all of which may be space-like separated. We argue that one significant way of characterising types of money in space-time is via the "summoning" tasks they can solve: that is, how flexibly the money can be propagated to a desired space-time point in response to relevant information received at various space-time points. We show that S-m…

一个量子选择模型和所谓的经典类比

A Quantum Paradox of Choice and Purported Classical Analogues

我们最近考虑了召唤一个未知的量子态的任务，并证明了必要和充分条件，爱丽丝能够保证完成任务时，可能有几个可能的电话，其中她只需要响应一个。我们证明了，这些条件比Hayden和May先前建立的条件严格更强，因为Alice知道只有一个呼叫。我们引入了{ \it选择的量子悖论}的概念来总结这些结果的含义：爱丽丝被给予更多的选择来完成我们的任务版本，然而人们可以很容易地构建例子，我们的版本是不可能的，而海登-梅考虑的明显更简单的版本是可能的。芬克尔斯坦认为，人们可以在相对论的背景下识别类似的经典选择悖论。我们研究芬克尔斯坦提出的经典任务，并解释为什么他们似乎对我们不相似。