Spectroscopy with Quantum Sensors at the Nanoscale

非技术描述：光谱学是许多物理环境中的强大工具，其应用范围从基本物理性质的分析到化学、材料科学和生物成像中的样品分析。该项目旨在将光谱学中使用的强大技术转化为基于金刚石缺陷量子特性的新型传感器。这些光学活性缺陷（色心）具有相关的电子自旋，对磁场和电场，温度，压力等敏感，该项目将开发光谱技术，为量子领域量身定制，可以在金刚石中使用这些纳米级传感器。特别是，该项目将侧重于实现噪声光谱学，即测量随机场（特别是磁场）的空间和时间相关性，这在材料和生物科学中无处不在。通过将适用于量子传感器的新型噪声光谱技术与量子传感器本身的纳米级分辨率相结合，新型量子噪声光谱技术将能够以以前无法达到的尺度测量场。此外，该项目将为研究生和本科生提供广泛领域的培训机会，从磁共振到量子信息，以及电子和量子光学的实验技能。此外，该项目还将开展外联活动，包括钻石传感器演示。技术说明：利用单个量子系统的新型纳米级传感器的出现有望揭示我们对纳米电子学，光子学和磁性器件及其潜在物理现象的基本理解。这些新的量子探针，如金刚石中的氮空位中心，可以在以前无法达到的条件和空间分辨率下工作：它们可以非常接近感兴趣的系统，并以纳米级分辨率测量微小的磁场（或电场）。经过近年来的首次原理验证，这些传感器即将成为探索电磁设备和材料的变革性工具。 为了实现这一目标，这些自旋传感器不仅应该能够测量给定场的大小，更重要的是它的时间和空间相关性，这些相关性携带了有关基本物理特性的大部分信息。该项目的目标是将与金刚石自旋相关的量子传感器转换为强大的光谱仪，能够检测纳米级磁场的时空相关性，例如，生物或磁性材料动力学，具有以前无法达到的空间分辨率和灵敏度。此外，表征噪声谱对于设计有效的策略来抵消新兴量子器件中的退相干是至关重要的。该项目将结合联合收割机在噪声光谱学和量子数字滤波方面的专业知识，通过量子纳米级传感器实现噪声光谱的有效和完整重建。最终目标是开发一个新的量子数字噪声光谱学领域，基于噪声光谱学结合沃尔什数字滤波函数的完整基础，并将其应用于磁性样品及其结构和时空相关性的增强传感。具有金刚石中NV中心的量子数字噪声光谱，还结合NV的超分辨率寻址，将被应用于生物样品的纳米级磁共振成像和测量磁性2D材料的空间噪声相关性。这样的实验可以揭示被测样品的结构和动力学，从而对生物功能和磁相变的普遍性质产生新的见解。

Non-Technical Description: Spectroscopy is a powerful tool in many physical settings, with applications ranging from analysis of basic physical properties to sample analysis in chemistry, material science and bio-imaging. This project aims at translating the powerful techniques used in spectroscopy to a novel type of sensors, based on the quantum properties of defects in diamond. These optically active defects (color centers) have an associated electronic spin that is sensitive to magnetic and electric fields, temperature, pressure, etc. The project will develop spectroscopic techniques, tailored to the quantum realm, that can be implemented with these nanoscale sensors in diamond. In particular, the project will focus on achieving noise spectroscopy, that is, measuring spatial and temporal correlation of random fields (in particular magnetic fields), which are ubiquitous in materials and biological sciences. By combining novel noise spectroscopic techniques that work for quantum sensors, with the nanoscale resolution of the quantum sensors themselves, the novel quantum noise spectroscopy technique will be able to measure fields at scales not previously accessible. In addition, the project will provide opportunities for training graduate and undergraduate students in broad areas, ranging from magnetic resonance, to quantum information, as well as experimental skills in electronics and quantum optics. The project will in addition develop outreach activities, including a diamond sensor demo. Technical Description: The advent of novel nanoscale sensors exploiting individual quantum systems promise to shed light into our fundamental understanding of nano-electronics, photonics and magnetics devices, and their underlying physical phenomena. These novel quantum probes, such as the Nitrogen-Vacancy center in diamond, can perform in conditions and with a spatial resolution previously inaccessible: they can be brought very close to the system of interest and measure minute magnetic (or electric) fields with nanoscale resolution. After the first proof-of-principle demonstrations in recent years, these sensors are on the verge of becoming transformative tools for the exploration of electromagnetic devices and materials. To reach this goal, these spin sensors should be able not only to measure the magnitude of a given field, but more importantly its temporal and spatial correlations that carry most of the information about underlying physical properties. The goal of this project is to transform quantum sensors associated with spins in diamond into powerful spectrometers, able to detect spatiotemporal correlations of magnetic fields at the nanoscale due to, e.g., biological or magnetic materials dynamics, with a spatial resolution and sensitivity previously unattainable. Moreover, characterizing the noise spectrum is critical for devising effective strategies to counteract decoherence in emerging quantum devices. This project will combine expertise on noise spectroscopy and on quantum digital filtering to achieve an efficient and complete reconstruction of the noise spectrum via a quantum nanoscale sensor. The ultimate goal is to develop a new field of quantum digital noise spectroscopy, based on noise spectroscopy combined with the complete basis of Walsh digital filtering functions, and applying it to enhanced sensing of magnetic samples, and their structure and spatiotemporal correlations. Quantum digital noise spectroscopy with NV centers in diamond, also combined with super-resolution addressing of NVs, will be applied to nanoscale magnetic resonance imaging of biological samples and to measure spatial noise correlations of magnetic 2D materials. Such experiments could shed new light on the structure and dynamics of the measured samples, leading to new insights in biological functions and in universal properties of magnetic phase transitions.