标题： 哈代悖论在单光子自旋-轨道希尔伯特空间中的测试 显示英文标题

标题： Hardy's paradox tested in the spin-orbit Hilbert space of single photons

摘要： 我们通过使用单光子而不是光子对，对Lucien Hardy于1993年提出的量子“悖论”进行了实验测试。[Phys. Rev. Lett. 71, 1665 (1993)] 这是通过针对同一粒子的两个兼容自由度来实现的，即其自旋角动量，由光子偏振确定，以及其轨道角动量，这是一个与光学横向模式相关的属性。由于我们的实验涉及单个粒子，我们不能使用局域性来逻辑上强制非上下文性，因此必须仅基于可观测量的相容性来假设非上下文性。另一方面，我们的单粒子实验可以更简单地实现，并且比典型的双粒子实验具有更大的探测效率，在关闭探测漏洞方面具有潜在的未来优势。 显示英文摘要

摘要： We test experimentally the quantum ``paradox'' proposed by Lucien Hardy in 1993 [Phys. Rev. Lett. 71, 1665 (1993)] by using single photons instead of photon pairs. This is achieved by addressing two compatible degrees of freedom of the same particle, namely its spin angular momentum, determined by the photon polarization, and its orbital angular momentum, a property related to the optical transverse mode. Because our experiment involves a single particle, we cannot use locality to logically enforce non-contextuality, which must therefore be assumed based only on the observables' compatibility. On the other hand, our single-particle experiment can be implemented more simply and allows larger detection efficiencies than typical two-particle ones, with a potential future advantage in terms of closing the detection loopholes.