Silicon-vacancy color centers in phosphorous-doped diamond for bright single-photon emission under electrical pumping

高效和可扩展的单光子源（SPS）对于许多量子信息技术的发展至关重要，例如光量子计算机和无条件安全通信线路。基于量子点的SPS在过去二十年中取得了很大进展，但在环境条件下，它们正在被金刚石和相关宽带隙半导体中色心的最新进展所克服。色心是晶格中的点缺陷，其行为几乎像孤立的原子。这种特性允许获得明亮的光致发光和具有尖锐发射光谱的电致发光，这在环境条件下无法用任何其他量子光电系统实现。然而，设计基于这些发射器的可扩展和可重复的技术仍然具有挑战性。特别是，很难将它们与实现高亮度和控制所需的光子和电子纳米结构精确地联合收割机结合。本项目旨在开发和研究一种新型的钻石上的明亮SPS，其在环境条件下工作，并且可以有效地电驱动。该项目将产生跨学科的合作，它是基于两个最近提出的概念。首先，为了增强色心的发射特性，我们将使用平面天线，其能够从具有大折射率的材料实现大的提取效率和强的定向发射。这种方法不需要精细的光谱调谐，也不需要发射器在纳米级的精确定位，这对于制造和器件操作是有益的。第二，我们将采用一种新的电泵浦方案的基础上肖特基二极管，它给出了有效地注入少数载流子直接从金属的金刚石的可能性，它不需要复杂和昂贵的p-i-n和p-n金刚石结。我们将在厚度小于100 nm的金刚石膜上制造高质量的硅空位（SiV）中心，并在其上制作一个带有电极的平面天线，研究光泵浦下的光子发射特性（重点是亮度、方向性），并探索在室温和更高温度下电激发SiV中心的可能性。因此，我们将证明一个高效的芯片级SPS的概念，将作为，并激发，量子信息和量子通信的新的光子源。我们的活动还将产生纳米光子学和材料科学方面的宝贵知识，这些知识将转移到其他应用领域。

Efficient and scalable single-photon sources (SPSs) are crucial to the development of numerous quantum information technologies, such as optical quantum computers and unconditionally secure communication lines. SPSs based on quantum dots have shown much progress in the last two decades, but under ambient conditions they are being overcome by the recent advances in color centers in diamond and related wide-bandgap semiconductors. Color centers are point defects in the crystal lattice that behave nearly as isolated atoms. This property allows to obtain bright photo- and electroluminescence with a sharp emission spectrum, which cannot be achieved with any other quantum optoelectronic system under ambient conditions. However, it is still challenging to design scalable and reproducible technologies based on these emitters. In particular, it is difficult to precisely combine them with photonic and electronic nanostructures that are needed for achieving high brightness and control.This project aims at developing and investigating a novel class of bright SPSs on diamond, which operate under ambient conditions and that can be efficiently electrically driven. The project will generate an interdisciplinary collaboration and it is based on two recently proposed concepts. First, to enhance the emission properties of the color center we will use a planar antenna, which enables large extraction efficiencies and strong directional emission from materials with a large refractive index. This approach does not require fine spectral tuning nor precise positioning of the emitter at the nanoscale, which is beneficial for fabrication and device operation. Second, we will employ a novel electrical pumping scheme based on a Schottky diode, which gives the possibility of efficiently injecting minority carriers in diamond directly from the metal and it does not require complex and expensive p-i-n and p-n diamond junctions. We will create high-quality silicon-vacancy (SiV) centers in less than 100-nm-thick diamond membranes and build a planar antenna with electrodes on it. We will investigate the photon emission properties (focusing on brightness, directionality) under optical pumping and explore the possibility of electrical excitation of SiV centers at room an higher temperatures. Thus, we will demonstrate a proof of concepts of a highly efficient and chip-scale SPS that will serve as, and inspire, novel photonic sources for quantum information and quantum communication. Our activities will also generate valuable knowledge in nanophotonics and materials science, which shall be transferred to other application areas.