title: Lateral manipulation of atomic vacancies in ultrathin insulating films.
abstract: During the last 20 years, using scanning tunneling microscopy (STM) and atomic force microscopy, scientists have successfully achieved vertical and lateral repositioning of individual atoms on and in different types of surfaces. Such atom manipulation allows the bottom-up assembly of novel nanostructures that can otherwise not be fabricated. It is therefore surprising that controlled repositioning of virtual atoms, i.e., atomic vacancies, across atomic lattices has not yet been achieved experimentally. Here we use STM at liquid helium temperature (4.5 K) to create individual Cl vacancies and subsequently to laterally manipulate them across the surface of ultrathin sodium chloride films. This allows monitoring the interactions between two neighboring vacancies with different separations. Our findings are corroborated by density functional theory calculations and STM image simulations. The lateral manipulation of atomic vacancies opens up a new playground for the investigation of fundamental physical properties of vacancy nanostructures of any size and shape and their coupling with the supporting substrate, and of the interaction of various deposits with charged vacancies.
authors.affiliation: †Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 d, Box 2414, BE-3001 Leuven, Belgium.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.affiliation: ‡Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via Cozzi 55, I-20125 Milano, Italy.
authors.forename: Hsin-Yi Tiffany
authors.initials: HY
authors.lastname: Chen
authors.affiliation: †Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 d, Box 2414, BE-3001 Leuven, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Schouteden
authors.affiliation: †Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 d, Box 2414, BE-3001 Leuven, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Lauwaet
authors.affiliation: †Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 d, Box 2414, BE-3001 Leuven, Belgium.
authors.forename: Ewald
authors.initials: E
authors.lastname: Janssens
authors.affiliation: †Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 d, Box 2414, BE-3001 Leuven, Belgium.
authors.forename: Chris
authors.initials: C
authors.lastname: Van Haesendonck
authors.affiliation: ‡Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via Cozzi 55, I-20125 Milano, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Pacchioni
authors.affiliation: †Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 d, Box 2414, BE-3001 Leuven, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Lievens
keywords: density functional theory; lateral vacancy manipulation; scanning tunneling microscope; ultrathin insulating films; vacancy−vacancy interaction