Probing electron beam induced effects at the single atom and defect level

Control of matter at the atomic scale is the key to building structures atom-by-atom. Currently only a handful of tools exist which have the precision to affect structures at the single atom level – the scanning transmission electron microscope (STEM) is one of these. The STEM provides the capability to routinely detect single atoms, due to an atom-sized electron beam. Typically any beam-induced effects in matter is regarded by microscopists to be “beam damage” however if proper control is attained then this may indeed be an excellent route toward atomic fabrication.



In order to realize this, fast and accurate extraction of atomic coordinates from image data is required, followed by control of the electron beam in relation to those coordinates. The extraction of coordinates has not been reliable or fast enough for live operation using standard blob detection or even neural networks, however here we utilize deep ensembles to robustly predict atom coordinates on the order of milliseconds. Given this, we then position the electron beam to selectively remove single atoms or create single defects from the system with extreme precision. This is demonstrated in both graphene and MoS₂.