Structured Electron Interferometry

这个项目的目标是实现和扩展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光子（光的最小单位）作为核心组成部分。然而，光子的波浪形性质仍然对其应用的最小长度尺度施加了基本限制。许多量子测量协议也可以用物质波来实现，但是用于产生、操纵、应用和探测物质波的技术并不像用于光子的技术那样发达。本项目在电子显微镜中开发新的量子技术，如利用电子进行无相互作用测量，并将其应用于探索纳米尺度上的各种现象。这将提供新的量子电子显微镜工具，可用于减少量子设备的尺寸，类似于传统的电子显微镜使经典计算组件的尺寸减小。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，该项目还将吸引一年级STEM专业的学生，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，为他们在暑期进入第二年提供“桥梁”。该项目开发和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。纳米级衍射全息图提供了一种相干地操纵单个电子的相位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分布的自由电子波函数，这为探测纳米等离子体的手性和空间相干性提供了一种新的方法。电子透明相位光栅也可以作为优化的电子分束器，在这个项目中用于制造具有大路径分离的电子干涉仪，用于测量纳米尺度的电场和磁场。研究人员还探索了无相互作用的测量方案，使高分辨率的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。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.