Atomic Scale Synthesis using Scanning Transmission Electron Microscopy

Point defects and regular arrays of point defects in otherwise pristine materials can imbue a material with new and useful functional properties. Nanopores, single-atom catalysts, and color and spin centers for quantum applications are examples. In particular, quantum defects are central in several nascent technologies for quantum optics and sensing. However, their full potential cannot be realized until these defects can be created and placed exactly where and how they are needed. Current lithographic techniques are orders of magnitude too imprecise. The scanning transmission electron microscope (STEM), a workhorse instrument in materials characterization, can not only be used to observe dynamic processes with atomic resolution, but also drive and control synthesis with atomic precision. Through custom control of the electron beam position that actively feeds back on image, spectroscopy, and other data streams, it’s possible to use focused beam energy to precisely initiate and interrupt desired transformations. This can be used for generating point defects, drilling and milling materials, changing phase, modifying bond coordination, and positioning dopants. Presented here are recent results highlighting advancements towards such a “synthescope”[1], insights into beam drilling processes [4,5], demonstration of patterning of arrays of dopants [3], and methods to deliver dopant atoms to the sample, in situ [2]. Developing this combination of experimental methods provides a window into dynamic synthesis processes at fundamental length scales and a path towards fabricating materials and devices with atomically precise components for quantum information science applications.