Shining potential of missing atoms

Single nitrogen vacancy created in hexagonal boron nitride by electron irradiation. In this filtered and colored scanning transmission electron microscopy image, the nitrogen atoms show brighter contrast, and the vacancy is visible as triangular dark contrast on the top left. Toma Susi / University of Vienna (CC-BY) Single-atom vacancies in atomically thin insulators created in ultra-high vacuum Single photons have applications in quantum computation, information networks, and sensors, and these can be emitted by defects in the atomically thin insulator hexagonal boron nitride (hBN). Missing nitrogen atoms have been suggested to be the atomic structure responsible for this activity, but it is difficult to controllably remove them. A team at the Faculty of Physics of the University of Vienna has now shown that single atoms can be kicked out using a scanning transmission electron microscope under ultra-high vacuum. The results are published in the journal Small . Transmission electron microscopy allows us to see the atomic structure of materials, and it is particularly well suited to directly reveal any defects in the lattice of the specimen, which may be detrimental or useful depending on the application.