EAGER: Investigation of local strain and single photon emitters in two-dimensional materials

非技术描述：单光子发射器(SPE)以单粒子(光子)的形式发光，是计算、通信和密码学等领先量子信息技术的重要光源。为了将SPE与微型化器件集成在一起，许多研究人员将重点放在了固态系统上，因为它们可以利用现有的纳米制造技术进行精确的制造和控制。近年来，二维(2D)材料中的SPE被报道，这种材料只有纳米级的厚度。这极大地扩展了SPE在芯片上可扩展集成的可能性。然而，发射的光子的颜色(能量)很难控制，因为控制2D材料中单光子发射的基本原理并不完全清楚，从而导致SPE行为可能看起来是随机的。在这个项目中，研究团队开发了一种专门设计的带有尖锐尖端图案的微观设备，以定量确定2D材料中应变或机械变形的强度和形状如何决定或改变SPE的性能。此外，研究团队通过制作一系列解释基本概念的短视频，并在广泛的社交媒体平台上分发视频，向中学生介绍微型人工结构，就像本项目中使用的那样，使研究团队能够接触到大量观众。这些教育资源向中学生介绍一些有趣的、不需要高等数学就能理解的主题，而且通常不包括在中学课程中。技术说明：虽然室温下层状六方氮化硼(HBN)中的SPE具有高光子纯度、明亮的发射和良好的量子效率，但它们表现出极不均匀，以随机能量发射广泛的光子。这限制了SPE在量子信息科学和技术中的应用，例如芯片上集成的量子光子电路。本项目将使用专门设计的多尖端平台来研究具有可调局部应变的SPE，并对hBN中局部应变与SPE之间的关系进行全面的研究。多尖端平台通过仔细设计尖端的几何形状和分布，提供了控制应变的能力，为可控应变工程开辟了机会。研究小组对现有SPE及其周围施加单轴、双轴和三轴拉伸和/或压缩应变，以定量确定SPE的强度和取向相关性，并研究引起SPE各种发射能量的基本原理。除了研究固有的SPE外，还有意诱导高应变来研究SPE的形成过程。该项目促进了对hBN中局部毒株与SPE之间关系的理解。本项目中使用的多尖端平台可以直接扩展到其他2D材料，以研究2D材料中应变诱导的光-物质相互作用，如过渡金属二碳化合物中的SPE和石墨烯中的伪磁场，并探索其输运、拓扑和量子行为。该项目由材料研究部的电子和光子材料计划和既定的刺激竞争研究计划(EPSCoR)联合资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical description:Single photon emitters (SPEs), which emit light as single particles (photons), are important light sources for leading quantum information technologies, such as computation, communication, and cryptography. To integrate SPEs with miniaturized devices, many researchers focus on solid-state systems because they can be fabricated and controlled precisely using current nanofabrication techniques. In recent years, SPEs have been reported in two-dimensional (2D) materials, which have only nanometer-scale thicknesses. This greatly expands the possibility of scalable integration of SPEs on a chip. However, the color (energy) of emitted photons is difficult to control because the fundamental principles that govern single photon emission in 2D materials are not entirely understood, leading to SPE behavior that may appear to be random. In this project, the research team develops a specially-designed microscopic device patterned with sharp tips to quantitatively determine how the strength and shape of strain, or mechanical deformation, in 2D materials determines or alters the performance of SPEs. In addition, the research team introduces middle-school students to micro-artificial structures, like the one used in this project, by creating a series of short videos explaining fundamental concepts and distributing the videos over a wide range of social media platforms, allowing the research team to reach a large audience. These educational resources introduce middle-school students to topics that are interesting, do not require advanced mathematics to understand, and are generally not included in a middle-school curriculum.Technical description:While SPEs in layered hexagonal boron nitride (hBN) at room temperature take advantage of high photon purity, bright emission, and favorable quantum efficiencies, they exhibit extreme inhomogeneity, emitting photons at random energies spanning a broad range. This limits the suitability of SPEs for applications in quantum information science and technology, such as on-chip integrated quantum photonic circuits. This project will use a specially-designed multi-tip platform to investigate the SPEs with tunable local strain and perform a comprehensive study of the relationship between local strain and SPEs in hBN. The multi-tip platform provides the capability to control strain through careful design of the tip geometry and distribution, opening up opportunities in controllable strain engineering. The research team applies uniaxial, biaxial, and triaxial tensile and/or compressive strain on and around existing SPEs to quantitatively determine the strength and orientation dependence and investigate the fundamental principles that give rise to a variety of emission energies from SPEs. In addition to studying intrinsic SPEs, high strain is intentionally induced to investigate the formation process of SPEs. This project advances the understanding of the relationship between local strain and SPEs in hBN. The multi-tip platform used in this project can be directly extended to other 2D materials to investigate strain-induced light-matter interactions in 2D materials, such as SPEs in transition metal dichalcogenides and pseudo-magnetic fields in graphene, and explore their transport, topological, and quantum behaviors.This project is jointly funded by Electronic and Photonic Materials program in the Division of Materials Research and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.