Description of the project. Efficient Chip-Integrated Photon Counting Detectors

提出了一种基于多路复用芯片集成瞬时耦合超导薄膜的新型光电探测器。这种方法可以实现高达数百个光子的单光子分辨率，比目前的设备提高了一百倍。我们的团队在epsrc资助下与Peter Smith （ORC, Southampton）和Sae Woo Nam （NIST Boulder）的团队合作开发了瞬时耦合光子计数探测器。这个概念是硅上硅波导被制造得足够接近芯片表面，使得沉积在表面的薄金属薄膜吸收导模的倏逝场。在这里，我们利用了这种探测器设计的一个独特方面：没有被探测器吸收的光保持在引导模式。因此，倏逝耦合实现了一种高效、高度可扩展的方案，该方案将一系列许多检测元素链接在一起。我们将开发具有两种类型的器件，它们在时序和数字分辨率方面提供互补的性能：过渡边缘传感器（TESs）和超导纳米线单光子探测器（SNSPDs）。在孤立的情况下，这些元素充满一个（SNSPD）或几个（TES）光子。有效的多路复用避免了元件饱和，同时可以同时检测多个激励。该项目旨在提供第一个单光子分辨率超过100个光子的多路复用探测器。这项工作将包括器件建模、量子探测器层析成像的表征，以及对多路探测器极限的理论研究。该学生还将与NQIT光子学研究人员合作，推进光子量子模拟器和基于纠缠的量子随机数发生器（QRNG）的应用。

We propose a new type of photodector based on multiplexed chip-integrated evanescently coupled superconducting films. This approach can achieve single-photon resolution up to hundreds of photons- a hundred-fold improvement over current devices. Our team developed evanescently coupled photon counting detectors in an EPSRC-funded collaboration with the groups of Peter Smith (ORC, Southampton) and Sae Woo Nam (NIST Boulder).The concept is that silica-on-silicon waveguides are fabricated sufficiently close to the chip surface so that thin metal films deposited on the surface absorb the evanescent field of the guided mode. Here, we leverage a unique aspect of this detector design: light that is not absorbed by a detector remains in the guided mode. The evanescent coupling therefore enables an efficient, highly scalable scheme that chains together a series of many detection elements. We will develop devices with two types of elements that provide complementary performance in timing and number resolution: transition edge sensors (TESs) and superconducting nanowire single-photon detectors (SNSPDs). In isolation, these elements are saturated with one (SNSPD) or a few (TES) photons. Effective multiplexing avoids element saturation while detecting many excitations in sum.This project aims to deliver the first multiplexed detector with single-photon resolution extending over a hundred photons. The work will include device modelling, characterisation by quantum detector tomography, and a theoretical study on the limits of multiplexed detectors. The student will also work alongside NQIT photonics researchers to progress application in photonic quantum simulators and an entanglement-based quantum random number generator (QRNG)