NIRT: Nanoscale Magnetic Microscopy with Multi-Photon Absorption Polymers and Y-Junction Nanotubes

该提案是响应纳米尺度科学与工程计划，NSF 01-157，类别NIRT而收到的。它侧重于纳米尺度下表面自旋成像的创新方法，包括三种MRFM（磁共振力显微镜）方案和一种新的使用巨磁电阻（GMR）检测的非机械自旋传感方案。一个由一名凝聚态物理学家、一名物理化学家、一名材料科学家和一名理论物理学家组成的研究小组将设计和开发用于MRFM和MFM（磁力显微复制）的纳米级探针。碳纳米管和多光子吸收（MPA）制造的聚合物悬臂梁，具有线性和各种分叉几何形状，将用于样品自旋的压阻、光波导和射频阻抗检测，其预期灵敏度达到单自旋水平。将合成一种新型阿图克大小的铁磁纳米棒，并将其连接到悬臂梁上，用作梯度发生器/自旋探针。除了单独的磁自旋传感器外，MRFM传感器阵列也将被制造出来，每个传感器都有一个集成的三维射频微线圈，通过MPA制造，促进纳米级功能MRI的空间和时间自旋相关测量。将自旋探测技术向单自旋水平推进，在信息技术、医学和科学探索等领域具有潜在的应用前景。磁流变调频（MRFM）正在发展成为一种灵敏度最高的测量技术，将在这一目标中发挥重要作用。分子尺度的器件，如碳和其他类型的纳米管，也将扮演越来越重要的角色。为了实现这一目标，必须消除几个障碍，例如热噪声，其光谱函数定义了一组参数，在寻求单自旋检测，三维分子成像，动态可视化等方面进行优化。另一个障碍是使用可见光的传统光学检测，其波长大于谐振磁传感器所需的物理尺寸。本课程的方法旨在克服这些障碍。除了四名高级人员外，这个跨学科的研究项目将涉及许多研究生，本科生，以及在夏季的几个月里选择的高中生，涵盖广泛的主题，如纳米尺度磁强计，微纳米制造，碳纳米管合成，多光子吸收，纳米磁铁合成，以及磁性，纳米管和半导体的理论方面。

This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 01-157, category NIRT. It focuses on innovative approaches to nanoscale subsurface spin imaging, including three MRFM (magnetic resonance force microscopy) schemes and one novel non-mechanical spin sensing scheme using giant magnetoresistance (GMR) detection. A research team composed of a condensed matter physicist, a physical chemist, a materials scientist and a theoretical physicist will design and develop nanoscale probes for MRFM as well as MFM (magnetic force microcopy). Carbon nanotube and multi-photon absorption (MPA) fabricated polymer cantilevers, in linear and various forked geometries, will be employed for piezoresistive, optical waveguide and RF impedance detection of specimen spins, with anticipated sensitivities to the single spin level. Novel attogram-sized ferromagnetic nanorods will be synthesized and attached to the cantilevers for use as gradient generators/spin probes. In addition to individual magnetic spin sensors, arrays of MRFM sensors will be made, with each sensor having an integrated three-dimensional radio frequency microcoil fabricated via MPA, facilitating spatial and temporal spin correlation measurements toward nanoscale functional MRI. There is much to be gained by advancing spin-detection technology toward the single-spin level, with potential applications in information technology, medicine and scientific exploration. MRFM, which is developing into a most highly sensitive measurement technique, stands to play a major role in this goal. Molecular-scale devices, such as carbon and other types of nanotubes, will play an increasingly important role as well. To reach this goal, several impediments must be obviated, such as thermal noise, the spectral function of which defines a set of parameters to be optimized in the quest for single spin detection, 3-D molecular imaging, dynamic visualization and beyond. Another impediment is the traditional optical detection using visible light, the wavelength of which is larger than the required physical dimensions of the resonating magnetic sensor. The approaches of this program are designed to overcome these obstacles. In addition to the four senior personnel, this interdisciplinary research program will involve numerous graduate students, undergraduates, and select high school students during summer months, covering a broad range of topics such as nanoscale magnetometry, micro and nanofabrication, carbon nanotube synthesis, multi-photon absorption, nanomagnet synthesis, and theoretical aspects of magnetism, nanotubes and semiconductors.