Discussions about quantum interference, indistinguishability and superpostion between quantum states goes back to the beginning of quantum mechanics, but the theoretical problem concerning quantitative measures for quantum coherence was only recently solved by Baumgratz et al. [Phys. Rev. Lett. 113 140401 (2014)]. Since then many works have explored one of the possible coherence measures, the l1 norm, which has not yet been experimentally obtained for spatial photonic states in high dimensions. In this article we study states prepared with photons crossing multiple slits and implement the theoretical proposal of T. Paul and T. Qureshi [ Phys. Rev. A 95 042110 (2017)] to determine experimentally the l1 norm of qutrit states. We analyze the method validity and present an alternative for states in which one of their assumptions does not apply. We also discuss the requirements necessary for using an interference pattern for measuring quantum coherence of qudits by treating the measure-operator that describe the detection optical configuration as path-markers, relating them with the quantum coherence determination.

中文翻译：

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空间光子量子的量子相干性：实验测量和路径标记分析

关于量子干涉、量子态之间的不可区分性和叠加的讨论可以追溯到量子力学的开端，但是关于量子相干性的定量测量的理论问题直到最近才由 Baumgratz 等人解决。[物理。牧师莱特。113 140401 (2014)]。从那时起，许多工作探索了一种可能的相干性度量，即 l1 范数，该范数尚未通过实验获得高维空间光子状态。在本文中，我们研究了光子穿过多个狭缝准备的状态，并实现了 T. Paul 和 T. Qureshi [ Phys. Rev. A 95 042110 (2017)] 通过实验确定 qutrit 状态的 l1 范数。我们分析了方法的有效性，并为其中一个假设不适用的状态提供了一种替代方法。