LEAPS-MPS: Electric field sensing with nitrogen vacancy centers and chemical tuning of the diamond host

该奖项全部或部分根据2021年美国救援计划法案（公法117-2）资助。非技术描述。钻石具有许多特性，使其价值远远超出其作为宝石的用途。值得注意的是，金刚石拥有一个敏感的磁场和电场检测器：氮空位（NV）中心。这样的NV中心可以用来感测磁性物体，并有可能在未来的量子计算机中用作量子比特（qubit）。金刚石的化学惰性，它不愿意改变或被修改，这对材料化学家，物理学家和工程师来说既是一个挑战，也是一个机会。改变金刚石表面上的化学键允许连接分子基团和锚定点以进行测量和检测。在这个LEAPS-MPS项目中，PI和他的团队将探索金刚石的表面化学，并研究NV中心发出的光如何随着施加的电压而变化。纳米级金刚石的表面化学和NV中心的行为将同时进行研究，其长期目标是制造更先进的量子传感器。本科生将学习先进的化学和光谱技术，包括使用斯坦福大学同步加速器辐射光源。人才招聘是与黑人领导和机会中心（BLOC）和其他学生组织在圣何塞州立大学合作。该项目将提供严格和广泛的研究经验，通过提供执行研究项目，管理故障排除，准备有影响力的研究演示文稿并为未来的成功建立简历的技能，为科学家和工程师的成功职业生涯做好准备。在这个LEAPS-MPS项目中，PI将探索新的途径来化学活化尺寸为25至100 nm的纳米级高压高温纳米级金刚石的表面，以产生新的共价键，并检查NV中心的物理性质。通过调整金刚石主体的表面偶极矩，研究人员将研究一个基本上未开发的空间与光谱电化学的NV电压传感。金刚石表面的活化将在惰性条件下用湿化学发生，并且一系列亲核试剂与“活化的”金刚石结构反应。金刚石结构的原子和分子结构的确认将与重叠的表面敏感技术发生，包括X射线光电子能谱和基于同步加速器的X射线光谱在斯坦福大学同步辐射光源。将表面改性的样品沉积在透明导电电极上，并在定制显微镜中跟踪NV中心荧光作为施加电压的函数。一系列的电压扫描参数进行修改，以了解NV中心如何可以切换其荧光电荷状态之间。一个工作模型，然后产生解释的NV中心的荧光特性作为一个功能的表面偶极矩，电荷密度和电荷身份。 这个钻石项目由来自许多学科的高度多样化的研究人员组成，包括物理科学，生命科学和工程学科。研究人员在项目周期内获得一套先进的技能，并将能够成功申请博士课程，在国家实验室工作或毕业后进入工业岗位。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Non-technical Description. Diamond has many properties that make it valuable well beyond its use as a gemstone. Notably, diamond hosts a sensitive detector of magnetic and electric fields: the nitrogen vacancy (NV) center. Such NV centers can be used to sense magnetic objects and have potential for use as quantum bits (qubits) in the quantum computers of the future. Diamond’s chemical inertness, its reluctance to change or be modified, is both a challenge and an opportunity for materials chemists, physicists and engineers. Changing chemical bonds on the surface of diamond allows for the attachment of molecular groups and anchoring points for measurement and detection. In this LEAPS-MPS project, the PI and his team will explore the surface chemistry of diamond and investigate how the light given off by the NV center changes with an applied voltage. The surface chemistry of nanoscale diamonds and the behavior of the NV center will be simultaneously examined with the long-term aim of making a more advanced quantum sensor. Undergraduate students will learn advanced chemistry and spectroscopy techniques, including use of the Stanford Synchrotron Radiation Lightsource. Recruitment of talent is in collaboration with the Black Leadership and Opportunity Center (BLOC) and other student-based organizations at San Jose State University. This project will provide rigorous and wide-ranging research experiences to prepare scientists and engineers for a successful career by providing the skills to execute a research project, manage troubleshooting, prepare an impactful research presentation and build their resume for future success.Technical Description. In this LEAPS-MPS project, the PI will explore new routes to chemically activate the surface of nanoscale high-pressure high-temperature nanoscale diamonds 25 to 100 nm in size to generate new covalent bonds and examine the photophysics of NV centers. By tuning the surface dipole moment of the diamond host, researchers will investigate a largely unexplored space of NV voltage sensing with spectroelectrochemistry. Activation of the diamond surface will occur with wet chemistry under inert conditions and a series of nucleophiles are reacted with the “activated” diamond constructs. Confirmation of the atomic and molecular structure of the diamond constructs will occur with overlapping surface sensitive techniques including X-ray photoelectron spectroscopy and synchrotron-based X-ray spectroscopies at the Stanford Synchrotron Radiation Lightsource. The surface modified samples are deposited onto transparent conducting electrodes and NV center fluorescence is tracked as a function of applied voltage in a custom microscope. A series of voltage sweep parameters are modified to understand how the NV center can toggle between its fluorescent charge states. A working model is then generated to explain the NV center fluorescent properties as a function of surface dipole moment, charge density and charge identity. This diamond project is conducted by a highly diverse cohort of researchers from many disciplines including the physical sciences, life sciences and engineering disciplines. Researchers acquire an advanced skill set during the project cycle and will be able to successfully apply to PhD programs, work at national laboratories or enter into industrial positions upon graduation.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.