Yard Patrick, Jones Alex E, Paesani Stefano, Maïnos Alexandre, Bulmer Jacob F F, Laing Anthony
Quantum Engineering and Technology Laboratories, School of Physics and Department of Electrical and Electronic Engineering, University of Bristol, Bristol, United Kingdom.
Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
Phys Rev Lett. 2024 Apr 12;132(15):150602. doi: 10.1103/PhysRevLett.132.150602.
Multiphoton interference is at the heart of photonic quantum technologies. Arrays of integrated cavities can support bright sources of single photons with high purity and small footprint, but the inevitable spectral distinguishability between photons generated from nonidentical cavities is an obstacle to scaling. In principle, this problem can be alleviated by measuring photons with high timing resolution, which erases spectral information through the time-energy uncertainty relation. Here, we experimentally demonstrate that detection can be implemented with a temporal resolution sufficient to interfere photons detuned on the scales necessary for cavity-based integrated photon sources. By increasing the effective timing resolution of the system from 200 to 20 ps, we observe a 20% increase in the visibility of quantum interference between independent photons from integrated microring resonator sources that are detuned by 6.8 GHz. We go on to show how time-resolved detection of nonideal photons can be used to improve the fidelity of an entangling operation and to mitigate the reduction of computational complexity in boson sampling experiments. These results pave the way for photonic quantum information processing with many photon sources without the need for active alignment.
多光子干涉是光子量子技术的核心。集成腔阵列能够支持产生具有高纯度和小尺寸的单光子明亮源，但是由不同腔产生的光子之间不可避免的光谱可区分性是扩展规模的一个障碍。原则上，通过以高时间分辨率测量光子可以缓解这个问题，这通过时间 - 能量不确定关系消除了光谱信息。在这里，我们通过实验证明，可以以足以干涉基于腔的集成光子源所需尺度失谐的光子的时间分辨率来实现检测。通过将系统的有效时间分辨率从200皮秒提高到20皮秒，我们观察到来自失谐6.8吉赫兹的集成微环谐振器源的独立光子之间的量子干涉可见度提高了20%。我们接着展示了如何使用对非理想光子的时间分辨检测来提高纠缠操作的保真度，并减轻玻色子采样实验中计算复杂度的降低。这些结果为无需主动对准的多光子源的光子量子信息处理铺平了道路。
