Experimental demonstration of quantum pigeonhole paradox
Ming-Cheng Chen, Chang Liu, Yi-Han Luo, He-Liang Huang, Bi-Ying Wang, Xi‐Lin Wang, Li Li, Nai-Le Liu, Chao‐Yang Lu, Jian-Wei Pan · Proceedings of the National Academy of Sciences · 2019
We experimentally demonstrate that when three single photons transmit through two polarization channels, in a well-defined pre- and postselected ensemble, there are no two photons in the same polarization channel by weak-strength measurement, a counterintuitive quantum counting effect called the quantum pigeonhole paradox. We further show that this effect breaks down in second-order measurement. These results indicate the existence of the quantum pigeonhole paradox and its operating regime.