Jones Alex E, Menssen Adrian J, Chrzanowski Helen M, Wolterink Tom A W, Shchesnovich Valery S, Walmsley Ian A
Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom.
Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom.
Phys Rev Lett. 2020 Sep 18;125(12):123603. doi: 10.1103/PhysRevLett.125.123603.
One of the central principles of quantum mechanics is that if there are multiple paths that lead to the same event and there is no way to distinguish between them, interference occurs. It is often assumed that distinguishing information in the preparation, evolution, or measurement of a system is sufficient to destroy interference. However, it is still possible for photons in distinguishable, separable states to interfere due to the indistinguishability of paths corresponding to possible exchange processes. Here we experimentally measure an interference signal that depends only on the multiparticle interference of four photons in a four-port interferometer despite pairs of them occupying distinguishable states.
量子力学的核心原理之一是，如果存在多条通向同一事件的路径且无法区分它们，则会发生干涉。人们通常认为，在系统的制备、演化或测量过程中存在可区分信息就足以破坏干涉。然而，由于与可能的交换过程相对应的路径具有不可区分性，处于可区分、可分离状态的光子仍有可能发生干涉。在此，我们通过实验测量了一种干涉信号，该信号仅取决于四端口干涉仪中四个光子的多粒子干涉，尽管其中的光子对处于可区分状态。
