Asban Shahaf, Mukamel Shaul
Department of Chemistry and Physics and Astronomy, University of California, Irvine, CA 92697-2025, USA.
Sci Adv. 2021 Sep 24;7(39):eabj4566. doi: 10.1126/sciadv.abj4566. Epub 2021 Sep 22.
Correlated photons inspire abundance of metrology-related platforms, which benefit from quantum (anti-) correlations and outperform their classical counterparts. While these mainly focus on entanglement, the role of photon exchange phase and degree of distinguishability has not been widely used in quantum applications. Using an interferometric setup, we theoretically show that, when a two-photon wave function is coupled to matter, it is encoded with “which pathway?” information even at low-degree of entanglement. An interferometric protocol, which enables phase-sensitive discrimination between microscopic interaction histories (pathways), is developed. We find that quantum light interferometry facilitates utterly different set of time delay variables, which are unbound by uncertainty to the inverse bandwidth of the wave packet. We illustrate our findings on an exciton model system and demonstrate how to probe intraband dephasing in the time domain without temporally resolved detection. The unusual scaling of multiphoton coincidence signals with the applied pump intensity is discussed.
关联光子激发了大量与计量学相关的平台，这些平台受益于量子（反）关联，并且性能优于其经典对应物。虽然这些主要集中在纠缠方面，但光子交换相位和可区分度的作用在量子应用中尚未得到广泛应用。通过干涉测量装置，我们从理论上表明，当双光子波函数与物质耦合时，即使在低纠缠度下，它也会被“哪条路径？”信息编码。我们开发了一种干涉协议，该协议能够对微观相互作用历史（路径）进行相敏区分。我们发现量子光干涉测量法促进了完全不同的一组时间延迟变量，这些变量不受波包逆带宽不确定性的限制。我们在一个激子模型系统上说明了我们的发现，并展示了如何在时域中探测带内退相，而无需时间分辨检测。我们还讨论了多光子符合信号与所施加泵浦强度的异常标度关系。
