By repeated trials, one can determine the fairness of a classical coin with a confidence which grows with the number of trials. A quantum coin can be in a superposition of heads and tails and its state is most generally a density matrix. Given a string of qubits representing a series of trials, one can measure them individually and determine the state with a certain confidence. We show that there is an improved strategy which measures the qubits after entangling them, which leads to a greater confidence. This strategy is demonstrated on the simulation facility of IBM quantum computers.

中文翻译：

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量子世界中的快速通信似然理论：用量子硬币和计算机进行测试

通过反复试验，人们可以通过随着试验次数的增加而增加的信心来确定经典硬币的公平性。量子硬币可以处于正面和反面的叠加状态，其状态通常是密度矩阵。给定一串代表一系列试验的量子比特，人们可以单独测量它们并以一定的信心确定状态。我们展示了一种改进的策略，可以在纠缠量子位后测量量子位，从而提高信心。这种策略在 IBM 量子计算机的模拟设施上得到了演示。