Structured Electron Interferometry

该项目的目标是实现和扩大由量子激发的电子测量。量子测量和量子信息技术的绝大多数现代发展都使用最小的光单位光子作为中心组件。然而，光子的波状性质仍然将其应用在最小的长度尺度上。这些量子测量协议中的许多也可以用物质波来实现，但用于产生、操纵、应用和探测物质波的技术没有光子技术那么发达。该项目在电子显微镜中开发了新的量子技术，例如使用电子进行无相互作用测量，并将它们应用于在纳米尺度上探索各种现象。这将提供新的量子电子显微镜工具，可用于缩小量子设备的尺寸，类似于传统电子显微镜如何使经典计算组件的尺寸缩小。除了为研究生和本科生提供高级显微镜和纳米科学方面的培训外，该项目还将吸引STEM专业一年级的学生，通过向他们介绍编程、数据分析、电子显微镜、纳米制造和光学物理，在夏季为他们提供进入二年级的“桥梁”。该项目开发并使用工具来准备和测量电子显微镜内自由电子波函数的相干性和相位性。纳米级的衍射全息图提供了一种相干地操纵单个电子的位相分布以及测量它们的方法。例如，衍射全息图可以产生具有螺旋相位分布的自由电子波函数，这为探测纳米尺度等离子体的手性和空间相干性提供了一种新的途径。电子透明位相光栅还可以作为电子的优化分束器，在该项目中使用它来创建具有大路径间隔的电子干涉仪，用于测量纳米级的电场和磁场。还探索了无相互作用的测量方案，这可以使高分辨率电子显微镜容易损坏的材料。该项目与广泛的科学和应用相联系，为一系列学科和行业的项目参与者提供了独特的机会。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The goal of this project is to enable and expand quantum-inspired measurements with electrons. The vast majority of modern developments in quantum measurement and quantum information technologies use photons, the smallest unit of light, as a central component. Yet the wavelike nature of photons still places fundamental limits on the smallest lengthscale at which this can be applied. Many of these quantum measurement protocols can be implemented with matter waves as well, but the technologies used to generate, manipulate, apply, and detect matter waves are not as well-developed as those for photons. This project develops new quantum techniques in the electron microscope, such as interaction-free measurements using electrons, and applies them to explore various phenomenon at the nanoscale. This will provide new quantum electron microscopy tools that can be used to reduce the size of quantum devices, similar to how conventional electron microscopes enabled the reduction in size of classical computing components. In addition to providing training to graduate and undergraduate students in advanced microscopy and nanoscience, this project will engage first-year STEM majors as well, providing a “bridge” over the summer into their second year by introducing them to programming, data analysis, electron microscopy, nanofabrication, and optical physics. The project develops and uses tools to both prepare and measure coherence and phase of free electron wavefunctions inside electron microscopes. Nanoscale diffraction holograms provide a way to coherently manipulate the phase profile of individiual electrons as well as measure them. For example, diffraction holograms can produce free electron wavefunctions with helical phase profiles that provide a new way to probe the chirality and spatial coherence of nanoscale plasmonics. Electron-transparent phase gratings can also serve as optimized beamsplitters for electrons, which are used in this project to create electron interferometers with large path separation, useful for measuring electric and magnetic fields at the nanoscale. Interaction-free measurement protocols are also explored, which could enable high resolution electron microscopy of easily damaged materials. The project connects with a broad spectrum of sciences and applications, enabling unique opportunities for project participants in a range of disciplines and industries.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.