Scanning Nitrogen-Vacancy Centre Magnetometer

扫描氮空位中心磁力计

• 批准号: 506455202
• 金额: --
• 依托单位: Johannes Gutenberg-Universität Mainz
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2023
• 资助国家: 德国
• 起止时间: 2022-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/506455202?language=en
• 关键词: Scanning; Nitrogen; Vacancy; Centre; Magnetometer

Quantum mechanical systems are inherently highly sensitive to external disturbances. This makes them ideal candidates for applications as sensors. Quantum sensors have gained significant interest in the development of novel technologies for measuring physical properties such as electromagnetic fields, thermodynamic properties such as temperature, and mechanical properties such as rotation. Compared to conventional sensing techniques based on classical physics, the key benefit of quantum sensors is their high precision. Here, we propose using a scanning nitrogen-vacancy (NV) centre microscope for sensing magnetic fields with ultra-high spatial and temporal resolution. A scanning NV magnetometer combines an optical confocal microscope with an atomic force microscope. A single negatively charged NV defect at the apex of a diamond atomic force microscopy tip is used as an atomic-sized sensor for measuring magnetic fields. For this, the quantum spin state of the NV centre is initialised optically and interacts with the magnetic field in a well-characterised manner. The resulting spin state is read out using optically detected magnetic resonance spectroscopy. This allows for precise and quantitative determination of the magnetic fields under ambient conditions with an easily detectable field of 5-10 µT. By scanning the sharp tip across the sample surface, the scanning NV magnetometer simultaneously records a map of the sample topography and the magnetic field present at the surface with a spatial resolution of down to ~10 nm. In addition to continuous optical and microwave pumping for measuring DC magnetic fields, pulsed measurement using established sequences of optical and microwave pulses allow for higher magnetic field sensitivity down to 0.5-1 µT as well as temporal resolution up to the GHz regime. NV centres' long and environment-dependent coherence times enable noise spectroscopy via spin relaxometry. Conventionally used techniques to image magnetization on the nanoscale such as spin-polarised scanning tunnelling microscopy and X-ray spectroscopy require dedicated sample preparation and complex experimental setups. Alternative techniques such as magnetic force microscopy are based on sensing stray fields. However, most of these techniques are perturbative and are not easily quantifiable. The key benefits of scanning NV microscopes are their wide compatibility with different samples and environments, and the non-perturbative nature of the measurement. Our proposal team has a diverse background with expertise in molecular spintronics, novel magnetic materials and NV magnetometry. We propose to make use of the unique features of the highly versatile scanning NV magnetometer setup for a wide spectrum of research projects ranging from imaging spin textures in magnetic materials in combination with magneto-transport measurements to detecting nuclear magnetic resonance in molecules.

量子力学系统天生对外界干扰高度敏感。这使得它们成为传感器应用的理想候选者。量子传感器在发展测量电磁场等物理性质、温度等热力学性质和旋转等力学性质等新技术方面获得了极大的兴趣。与基于经典物理的传统传感技术相比，量子传感器的关键优点是其高精度。在这里，我们建议使用扫描氮空位(NV)中心显微镜来传感具有超高空间和时间分辨率的磁场。扫描NV磁强计结合了光学共焦显微镜和原子力显微镜。在金刚石原子力显微镜尖端的单个带负电荷的NV缺陷被用作原子大小的传感器来测量磁场。为此，NV中心的量子自旋态被光学初始化，并以一种很好的方式与磁场相互作用。使用光学检测的磁共振光谱读出所得到的自旋态。通过扫描样品表面的尖端，扫描NV磁强计可同时记录样品表面的地图和样品表面存在的磁场，空间分辨率可达~10 nm。除了用于测量直流磁场的连续光学和微波泵浦外，使用已建立的光学和微波脉冲序列的脉冲测量还允许更高的磁场灵敏度(低至0.5-1µT)以及高达GHz制度的时间分辨率。NV中心与环境相关的长相干时间使噪声光谱能够通过自旋弛豫测量实现。传统上使用的在纳米尺度上成像磁化的技术，如自旋极化扫描隧道显微镜和X射线光谱分析，需要专门的样品制备和复杂的实验装置。替代技术，如磁力显微镜，是基于感应杂散场的。然而，这些技术大多是微扰的，不容易量化。扫描NV显微镜的主要优点是其与不同样品和环境的广泛兼容性，以及测量的非微扰性。我们的提案团队拥有不同的背景，拥有分子自旋电子学、新型磁性材料和NV磁测量方面的专业知识。我们建议利用高通用性扫描NV磁强计的独特功能进行广泛的研究项目，从成像磁性材料的自旋织构与磁传输测量相结合，到检测分子中的核磁共振。