EAGER: Manufacturing of Diamond Nanocrystals for Quantum Applications

这个早期概念的探索性研究赠款（EAGER）奖旨在研究金刚石晶体阵列纳米制造的基础科学和工程，用于许多新的应用，如量子计算，磁场传感，自旋电子学，加密和纳米医学。含有氮空位（NV）缺陷中心的金刚石纳米晶体显示出可以通过微波、光信号、电场和磁场控制的特性，从而使它们可用于无数的量子应用。为了用作量子器件的组件，每个纳米或微米尺寸的金刚石单晶应该优选地仅包含一种类型的NV缺陷中心，并且当排列成孤立的金刚石单晶阵列时，实现最大的灵敏度和单独的可寻址性。本项目开发了制造含有NV缺陷中心的金刚石单晶阵列的方法，NV缺陷中心优先沿沿着单个晶体学方向取向。此外，该项目还为研究生和本科生提供教育和培训，以促进劳动力发展和学术界或工业界的职业生涯。研究结果将传播给科学界，预计将对先进制造、纳米技术、量子信息科学、光电子学、医学、量子技术的最新技术采用金刚石薄膜或含有NV缺陷的块状晶体，这些缺陷不适合于宽范围的应用，因为NV缺陷是随机分布的，并且对于许多新颖的量子应用来说不能单独解决。该项目的目的是证明制造具有增强的NV缺陷中心择优取向的外延金刚石单晶阵列的概念验证。整个计划的科学依据是基于三个变革性假设，包括（1）偏压增强成核，用于在图案化单晶硅衬底上产生外延金刚石核阵列，随后生长金刚石晶体;（2）衬底取向的作用，促进基于平面原子密度的NV缺陷中心沿沿着111结晶方向的优先取向;以及（3）在通过微波等离子体增强化学气相沉积（MPECVD）的制造期间施加电场和/或磁场，用于NV缺陷中心的额外优先对准。该项目推进了对氮原位掺杂、金刚石成核和生长机制、衬底取向以及对NV缺陷中心施加的电场和/或磁场的作用的基本理解。金刚石纳米晶体的质量是通过对自旋状态可寻址性的定量表征来确定的，该定量表征基于纳米晶体暴露于微波和激光泵浦时的光发射变化，该激光泵浦使用光学检测的磁共振。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估而被认为值得支持。

This EArly-concept Grants for Exploratory Research (EAGER) award aims at studying the fundamental science and engineering for nanomanufacturing of diamond crystal arrays for use in many novel applications, such as, quantum computing, magnetic field sensing, spintronics, encryption, and nanomedicine. Diamond nanocrystals containing nitrogen-vacancy (NV) defect centers display properties that can be controlled by microwave, optical signal, electric and magnetic fields thereby making them useful for a myriad of quantum applications. To function as components of quantum devices, each nanometer or micrometer size diamond single crystal should preferably contain only one type of NV defect center and, when arranged into isolated diamond single crystal arrays, achieve the greatest sensitivity and individual addressability. This project develops approaches to manufacture diamond single crystal arrays containing NV defect centers that are preferentially oriented along a single crystallographic direction. In addition, the project provides education and training to graduate and undergraduate students towards workforce development and careers in academia or industry. The research findings are disseminated to the scientific community and expected to have significant impacts on several national initiatives such as advanced manufacturing, nanotechnology, quantum information sciences, optoelectronics, medicine, and national security.The state-of-the-art in quantum technology employs diamond thin films or bulk crystals containing NV defects that are unsuited for wide-spread use because the NV defects are randomly distributed and cannot be individually addressed for many of the novel quantum applications. The objective of the project is to demonstrate proof-of-concept for manufacturing of epitaxial diamond single crystal arrays with enhanced preferred orientation of the NV defect centers. The scientific justifications for the overall program are based on three transformative hypotheses that include (1) bias-enhanced nucleation for creating an array of epitaxial diamond nuclei on patterned single crystal silicon substrates followed by the growth of the diamond crystals; (2) role of substrate orientations promoting preferential orientation of the NV defect centers along 111 crystallographic direction based on planar atom density; and (3) application of electric and/or magnetic fields during manufacturing by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) for additional preferential alignment of the NV defect centers. The project advances the fundamental understanding of the roles of in situ doping by nitrogen, diamond nucleation and growth mechanisms, substrate orientation, and applied electric and/or magnetic fields on the NV defect centers. The quality of the diamond nanocrystals is determined by quantitative characterization of spin state addressability based on changes in optical emission upon exposure of the nanocrystals to microwave and laser pumping using optically detected magnetic resonance.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.