Title: Subjective nature of path information in quantum mechanics Show Chinese title

Title: 量子力学中路径信息的主观性质

Abstract: Common sense suggests that a particle must have a definite origin if its full path information is available. In quantum mechanics, the knowledge of path information is captured through the well-established duality relation between path distinguishability and interference visibility. If visibility is zero, a high path distinguishability can be obtained, which enables one with high predictive power to know where the particle comes from. Here we show that this perception of path information is problematic. We demonstrate the simultaneous observation of zero interference visibility and the complete absence of which-path information using a three-crystal interference setup. With a contradictory argument by grouping the crystals in different ways, we show that it is impossible to ascribe a definite physical origin to the photon pair even if the emission probability of one individual source is zero and full path information is available. Our findings shed new light on the physical interpretation of probability assignment and path information beyond its mathematical meaning and reshape our understanding of the whole and part in the context of distinguishability. Show Chinese abstract

Abstract: 常识认为，如果可以获得粒子的完整路径信息，那么该粒子必然具有确定的起源。 在量子力学中，路径可区分性和干涉可见度之间的双重关系捕捉了路径信息的知识。 如果可见度为零，则可以得到较高的路径可区分性，这使得一个人能够以高度的预测能力知道粒子来自何处。 在这里，我们表明这种对路径信息的理解存在问题。 我们通过一个三晶体干涉设置展示了零干涉可见度和完全缺乏哪条路径信息的同时观测。 通过对晶体以不同方式分组进行矛盾论证，我们证明即使单个源的发射概率为零且存在完整的路径信息，也无法将确定的物理起源归因于光子对。 我们的发现为超越数学意义的概率分配和路径信息的物理解释提供了新的视角，并重塑了我们在可区分性背景下对整体与部分的理解。