标题： 以光子为媒介的纠缠产生 显示英文标题

标题： Heralded generation of entanglement with photons

摘要： 光子的纠缠态是许多量子技术的基础。 由于缺乏有效的光子-光子相互作用，这些态的生成通常是概率性的。 在目前但本质上受限的生成技术中，称为后选择，目标光子在生成过程中被破坏性地测量。 相比之下，在替代方法——引导态生成中，通过检测辅助光子来验证所需态的成功创建。 引导态生成在几个关键方面优于后选择：它允许自由使用制备的态，可以通过多路复用任意提高成功概率，并提供了一种利用光子进行量子信息处理的可扩展途径。 在这里，我们回顾了引导纠缠光子态生成的理论提案和实验实现，以及实际实验误差的影响。 然后我们讨论了这些态在量子技术中的广泛应用，包括线性光学量子计算中的资源态、中继网络中的纠缠交换、基础物理和量子计量学。 显示英文摘要

摘要： Entangled states of photons form the backbone of many quantum technologies. Due to the lack of effective photon-photon interactions, the generation of these states is typically probabilistic. In the prevailing but fundamentally limited generation technique, known as postselection, the target photons are measured destructively in the generation process. By contrast, in the alternative approach -- heralded state generation -- the successful creation of a desired state is verified by the detection of ancillary photons. Heralded state generation is superior to postselection in several critical ways: It enables free usage of the prepared states, allows for the success probability to be arbitrarily increased via multiplexing, and provides a scalable route to quantum information processing using photons. Here, we review theoretical proposals and experimental realizations of heralded entangled photonic state generation, as well as the impact of realistic experimental errors. We then discuss the wide-ranging applications of these states for quantum technologies, including resource states in linear optical quantum computing, entanglement swapping for repeater networks, fundamental physics, and quantum metrology.