RII Track 4: Metrology and spectroscopy of individual nanomagnets dynamics using quantum sensor-based (NV- center) nano-magnetometry

RII 轨道 4：使用基于量子传感器（NV 中心）纳米磁力测量的单个纳米磁体动力学的计量学和光谱学

• 批准号: 2033210
• 负责人: Kapildeb Ambal
• 金额: $ 20.93万
• 依托单位: Wichita State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2033210&HistoricalAwards=false
• 关键词: RII; Track; Metrology; spectroscopy; individual

Magnetic nanostructures, referred to as nanomagnets, are the foundation of emerging information storage technologies such as magnetic random access memory (MRAM) devices. Explosive growth in information science and technology sectors demands new storage technologies that are smaller recording bits, densely packed, fast, low-cost, and energy-efficient. Therefore, the magnetic nanostructures used to build magnetic memory need to be small, fast, and uniform across many devices. However, identically engineered nanomagnets' performances deviate from each other due to geometric imperfections, non-uniform material compositions, and manufacturing-related defects. A detailed diagnosis of individual nanomagnets is necessary to unravel the effects of shape, sizes, and manufacturing imperfections on nanomagnets' properties. However, the measurement of nanomagnets' properties is complicated because they are small and buried under many layers. The proposed project aims to measure the properties of individual nanomagnets. The proposed measurement would expose what causes the nanomagnets' performances to deviate from each other. The proposed research will be performed with a collaborator at the University of Nebraska – Lincoln (UNL). The state-of-the-art research tools at the Nebraska Nanoscale Facility will be used to design, fabricate, and measure nanomagnets' properties. The obtained new knowledge will be implemented into the education plans, which empower the future STEM workforce.The confined geometry of magnetic nanostructures causes spin dynamics to deviate from bulk thin films. In addition to shifting the resonance frequency, multiple spin-wave modes are present. The strong inhomogeneity in the internal magnetic field at the edge allows spin-wave to localize within a few nanometers from the edge. Damages induced during nanopatterning, such as impurities, edge, and interface roughness, can significantly modify spin dynamics. The edges and defects' roles become critical with decreasing size as the spin dynamics deviate among nanomagnets due to a slight deviation in edge roughness and defect densities. The measurement of spin dynamics is complicated because nanomagnets are often buried under nonmagnetic layers, and both conventional metrology tools and routine magnetic measurements are not adequately sensitive. Furthermore, it is difficult to retrieve an individual nanomagnet's covert spin dynamics from the average response of many similar nanomagnets. The proposed research investigates the spectroscopy of spin-wave excitation modes characteristics of individual magnetic nanostructures. The overall goals are to understand the fundamental device physics that controls the dynamic properties of magnetic nanostructures and to understand the source of defects, non-uniformity, and geometrical imperfection among devices and their roles in device performances. The proposed novel method is scanning Nitrogen-Vacancy (NV-) center-based magnetometry combined with real-time locking and tracking of NV- center's magnetic resonance peak. The proposed approach leverage the unique properties of NV- centers whose magnetic resonance frequency shifts due to change in the magnetic field in the vicinity.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.

磁性纳米结构（称为纳米磁铁）是新兴信息存储技术（例如磁随机访问记忆（MRAM）设备）的基础。信息科学和技术领域的爆炸性增长需要新的存储技术，这些储存技术是较小的记录位，不足，快速，低成本和节能。因此，用于构建磁记忆的磁性纳米结构需要在许多设备上都小，快速且均匀。但是，由于几何缺陷，不均匀的材料组成和与制造相关的缺陷，纳米磁铁的性能相同彼此偏离。单个纳米磁体的详细诊断是要揭示形状，大小和制造缺陷对纳米磁体特性的影响的必要条件。但是，纳米磁体性质的测量很复杂，因为它们很小并且被埋在许多层中。拟议的项目旨在测量单个纳米磁体的性质。提出的测量将暴露导致纳米磁性表现彼此偏差的原因。拟议的研究将与内布拉斯加州大学 - 林肯大学（UNL）的合作者一起进行。内布拉斯加州纳米级设施的最先进的研究工具将用于设计，制造和测量纳米磁体的特性。获得的新知识将实施到教育计划中，从而赋予未来的STEM劳动力。磁性纳米结构的限制几何形状会导致旋转动力学偏离散装薄膜。除了移动共振频率外，还存在多个自旋波模式。边缘内部磁场中的强不均匀性使自旋波可以从边缘几纳米内定位。在纳米图案中诱导的损害，例如杂质，边缘和界面粗糙度，可以显着改变自旋动力学。由于边缘粗糙度和缺陷密度略有偏差，边缘和缺陷的作用随着纳米磁体的偏差而偏离纳米磁体的尺寸而变得至关重要。旋转动力学的测量很复杂，因为纳米磁体通常被埋在非磁性层下，并且常规的计量工具和常规磁性测量都不适当敏感。此外，很难从许多类似的纳米磁体的平均响应中检索单个纳米磁体的秘密旋转动力学。拟议的研究研究了单个磁性纳米结构的自旋波兴奋模式的特征的光谱。总体目标是了解控制磁性纳米结构的动态特性的基本设备物理学，并了解设备之间的缺陷，不均匀性和几何缺陷及其在设备性能中的作用。所提出的新方法是扫描氮 - 胶囊（NV-）基于中心的磁力测定法，结合了实时锁定和NV-Center磁共振峰的跟踪。提出的方法利用了NV中心的独特性能，其磁共振频率由于附近磁场的变化而导致。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来评估被认为是宝贵的支持。

项目成果

An Efficient Method to Create High-Density Nitrogen-Vacancy Centers in Cvd Diamond for Sensing Applications

• DOI: 10.1016/j.diamond.2023.110472
• 发表时间: 2023-01
• 期刊: SSRN Electronic Journal
• 作者: Prem Bahadur Karki;Rupak Timalsina;M. Dowran;Ayodimeji E. Aregbesola;A. Laraoui;K. Ambal

Nitrogen-Vacancy Magnetic Relaxometry of Nanoclustered Cytochrome C Proteins

• DOI: 10.1021/acs.nanolett.3c03843
• 发表时间: 2024-01-11
• 期刊: NANO LETTERS
• 影响因子: 10.8
• 作者: Lamichhane，Suvechhya;Timalsina，Rupak;Laraoui，Abdelghani
• 通讯作者: Laraoui，Abdelghani