The origin of non-classicality in physical systems and its connection to distinctly quantum features such as entanglement and coherence is a central question in quantum physics. This work analyses this question theoretically and experimentally, linking quantitatively non-classicality with quantum coherence. On the theoretical front, we show when the coherence of an observable is linearly related to the degree of violation of the Kolmogorov condition, which quantifies the deviation from any classical (non-invasive) explanation of the multi-time statistics. Experimentally, we probe this connection between coherence and non-classicality in a time-multiplexed optical quantum walk. We demonstrate exquisite control of quantum coherence of the walker by varying the degree of coherent superposition effected by the coin, and we show a concomitant variation in the degree of non-classicality of the walker statistics, which can be accessed directly by virtue of the unprecedented control on ...

中文翻译：

---

通过量子相干性对非经典度的实验控制

物理系统中非经典性的起源以及与纠缠和相干性等明显量子特征的联系是量子物理学中的中心问题。这项工作从理论上和实验上分析了这个问题，将量化的非经典性与量子相干联系起来。在理论上，我们显示了一个可观测对象的相干性何时与违反Kolmogorov条件的程度线性相关，该条件量化了与多次时间统计的任何经典（非侵入性）解释的偏差。实验上，我们探讨了时分多路复用光量子漫游中相干性和非经典性之间的这种联系。通过改变硬币所影响的相干叠加程度，我们展示了对助行器量子相干性的精确控制，