Nanophotonic enhancement of solid-state quantum emitters

光子是量子信息的优秀载体。它们在很长一段时间内保持相干性，可以远距离传输，使它们成为量子技术的关键组成部分，包括安全的互联网、超越任何经典机器的计算机，以及有助于开发新药物和新材料的模拟器。然而，在实现这些目标之前，有许多障碍需要消除。光子很难按需产生，当产生光子时，它们以光速传播，这使得它们难以存储和同步，而且它们必须处于硅玻璃低损耗区域的波长，才能与光纤网络兼容。在攻读博士学位期间，我将利用固态量子发射器（如单个有机分子和晶体缺陷）来克服这些问题，在这两种情况下，与纳米光子结构耦合以有效地产生光子。固态分子二苯并泰甲苯的发射波长在780 nm到795 nm之间，与铷原子中的D1和D2跃迁相兼容。这种有前途的光子源发射相干窄带光子的概率很高，但很难总是将发射的光子收集到定义良好的光学模式。在这个博士学位期间，我将设计和制造一个垂直发射腔与一个储层，可以充满有机分子。一旦分子与腔体耦合，它就会以高速率垂直发射，进入一种与光纤非常匹配的模式。这将使新的量子干涉演示和分子发射与原子系统的界面成为可能。硅中碳缺陷的发射波长在1200纳米到1500纳米之间，这使得它们与远距离量子网络兼容。在攻读博士学位期间，我将设计和制造硅光子结构——硅芯片上的波导和导模腔——这将增强从这些缺陷中发射和收集光子的能力，使我能够构建一个集成的、按需的、电信兼容的光子源。在硅中，这些发射器受益于制造当前计算机芯片的巨大基础设施和投资，并将对量子通信和基于芯片的小型化量子计算和模拟产生革命性影响。在这个项目中，将使用几种新的显微镜和光谱学技术。更具体地说，我将使用一个定制的低温共聚焦显微镜来刺激光子的发射，并使用激光扫描荧光光谱来分析不同缺陷的光谱。这两种方法都代表了将在我的项目中使用的新颖方法。该博士学位与EPSRC的研究领域“新量子技术的量子物理学”、“量子光学与信息”、“量子器件组件和系统”、“光学器件和子系统”和“光子材料”保持一致。

Photons are excellent carriers of quantum information. They retain coherence for long periods of time and can be sent over large distances, making them key components of quantum technologies including a secure internet, computers that can surpass any classical machine, and simulators which will assist with the development of new medicines and materials. However, there are multiple roadblocks which need to be removed before these goals can be reached. Photons are difficult to generate on demand, when generated they travel at the speed of light making them difficult to store and synchronise, and they must be at a wavelength in the low-loss region of silica glass to be compatible with optical fiber networks. During this PhD I will overcome these problems using solid-state quantum emitters such as single organic molecules and crystalline defects, in both cases coupled to nanophotonic structures to generate photons efficiently. Emission from the solid-state molecule dibenzoterrylene is between 780 nm to 795 nm, making it compatible with the D1 and D2 transitions in rubidium atoms. This promising source of photons has a high probability to emit coherent, narrowband photons, but it is difficult to always collect the emitted photons to a well-defined optical mode. During this PhD I will design and fabricate a vertical-emitting cavity with a reservoir that can be filled with organic molecules. Once a molecule is coupled to the cavity it will emit vertically at a high rate into a mode that is well matched to an optical fiber. This will enable novel quantum interference demonstrations and for interfacing molecule emission with atomic systems. Emission from carbon defects in silicon is at wavelengths spanning 1200 nm to 1500 nm, making them compatible with long-distance quantum networks. During this PhD I will design and fabricate silicon photonic structures - waveguides and cavities in guided modes on a silicon chip - which will enhance the emission and collection of photons from these defects allowing me to build an integrated, on-demand, telecommunications compatible photon source. Being in silicon these emitters benefit from the huge infrastructure and investment in making current computer chips and will be transformative for quantum communication and miniaturised chip-based quantum computation and simulation. The use of several novel microscopy and spectroscopy techniques will be utilised during this project. More specifically, I will employ a bespoke cryogenic confocal microscope to stimulate the emission of photons and also laser-scanning fluorescence spectroscopy to analyse the spectra of varying defects. These both represent novel approaches to methodology that will be employed during my project. This PhD aligns with the EPSRC research areas "Quantum physics for new quantum technologies", "Quantum optics and information", "Quantum devices components and systems", "Optical devices and subsystems", and "Photonic materials".