CAREER: Theoretical Investigation of Single Photon Detectors for Quantum Technology: A Nano-structure Devices Approach

更广泛的影响-单光子探测器是几个重要的传统和量子技术应用的支持设备，如量子密钥分配，量子成像和单分子光谱学。尽管这些应用的重要性越来越大，但专门为单光子计数设计的紧凑型固态探测器和阵列的开发进展甚微。单光子p-n结探测器不提供必要的性能，并且它们的操作从未针对该应用进行过优化。PI打算通过提出一类基于半导体纳米结构的新型单光子探测器来解决这个问题，并通过开发一种新的数值模拟方法来进行设计和优化。发展的理论和模拟技术也将有助于研究纳米结构材料和器件中的载流子输运和光探测现象。教育计划包括发展本科和研究生课程，支持高中教师，以及为发展中国家提供教育计划。一个关键的特点是使用模拟工具，以改善教学的半导体物理和技术在所有教育水平。智力优点-PI提出了使用两个新的探测器的概念，工作在不同的物理原理，通过利用纳米结构的设备。所提出的设备结构旨在克服当前单光子检测器设计的一些缺点（暗和后脉冲计数、缺乏可调谐性和冷却的必要性），并提供额外的功能，例如可调谐性。第一种器件是基于多量子阱或量子点层中的子带间光吸收，随后是倍增区。第二种器件使用嵌入在高电子迁移率晶体管结构中的量子点层。在拟议的工作中，PI正在开发的一种新的数值模拟技术将用于设计和优化一类新的单光子探测器。新的数值模拟方法是基于一个微观模型，该模型描述了检测，倍增和载流子输运过程及其时间演化的细节。这种技术没有宏观模型的缺点，提供了一个更好的描述的物理和单光子探测器的操作，是互补的分析方法正在开发的其他小组。仿真技术也将被用来显示如何提高当前一代APD的性能。

Broader impact - Single photon detectors are the enabling devices for several important conventional and quantum technology applications, such as quantum key distribution, quantum imaging and single molecule spectroscopy. In spite of the growing importance of these applications, there has been little progress towards the development of compact solid-state detectors and arrays specifically designed for single photon counting. Single photon p-n junction detectors do not provide the necessary performance and their operation has never been optimized for this application. The PI intends to address this problem by presenting a novel class of single photon detectors based on semiconductor nano-structures and by developing a new numerical simulation approach for their design and optimization. The theory and simulation techniques developed will also be useful in the study of a broad range of carrier transport and light detection phenomena in nano-structured materials and devices.The educational plan includes developments in undergraduate and graduate programs, support for high school teachers, and an educational program for developing countries. A key feature is the use of simulation tools to improve the teaching of semiconductor physics and technologies at all educational levels.Intellectual Merit - The PI proposes the use of two novel detector concepts that work on different physical principles by taking advantage of nano-structure devices. The proposed device structures are intended to overcome some of the disadvantages (dark and afterpulse counts, lack of tunability and necessity of cooling) of the current single photon detector designs and provide additional functionalities, e.g. tunability. The first device is based on intersubband optical absorption in a multi-quantum-well or quantum dot layers, followed by a multiplication region. The second device uses a layer of quantum dots embedded in a high electron mobility transistor structure. In the proposed work, a new numerical simulation technique that the PI is developing will be used to design and optimize a new class of single photon detectors. The new numerical simulation approach is based on a microscopic model that describes the details of the detection, multiplication and carrier transport processes and their time evolution. This technique does not have the drawbacks of the macroscopic models, provides a better description of the physics and operation of single photon detectors, and is complementary to analytical methods being developed by other groups. The simulation technique will also be used to show how the performance of the current generation of APDs can be improved.