title: Quantitative Agreement between Electron-Optical Phase Images of WSe_{2} and Simulations Based on Electrostatic Potentials that Include Bonding Effects.
abstract: The quantitative analysis of electron-optical phase images recorded using off-axis electron holography often relies on the use of computer simulations of electron propagation through a sample. However, simulations that make use of the independent atom approximation are known to overestimate experimental phase shifts by approximately 10%, as they neglect bonding effects. Here, we compare experimental and simulated phase images for few-layer WSe_{2}. We show that a combination of pseudopotentials and all-electron density functional theory calculations can be used to obtain accurate mean electron phases, as well as improved atomic-resolution spatial distribution of the electron phase. The comparison demonstrates a perfect contrast match between experimental and simulated atomic-resolution phase images for a sample of precisely known thickness. The low computational cost of this approach makes it suitable for the analysis of large electronic systems, including defects, substitutional atoms, and material interfaces.
authors.affiliation: Peter Grünberg Institute 9 (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Borghardt
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Jülich, D-52425 Jülich, Germany.|Peter Grünberg Institute 5 (PGI-5), Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Winkler
authors.affiliation: Peter Grünberg Institute 1 (PGI-1) and Institute for Advanced Simulations (IAS-1), Forschungszentrum Jülich, D-52425 Jülich, Germany.|Institute for Theoretical Solid State Physics and European Theoretical Spectroscopy Facility, RWTH Aachen University, D-52056 Aachen, Germany.
authors.forename: Z
authors.initials: Z
authors.lastname: Zanolli
authors.affiliation: NanoMat / Q-Mat / CESAM and European Theoretical Spectroscopy Facility, Université de Liège (B5), B-4000 Liège, Belgium.
authors.forename: M J
authors.initials: MJ
authors.lastname: Verstraete
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Jülich, D-52425 Jülich, Germany.|Gemeinschaftslabor für Elektronenmikroskopie (GFE), RWTH Aachen University, D-52074 Aachen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Barthel
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Jülich, D-52425 Jülich, Germany.|Peter Grünberg Institute 5 (PGI-5), Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: A H
authors.initials: AH
authors.lastname: Tavabi
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Jülich, D-52425 Jülich, Germany.|Peter Grünberg Institute 5 (PGI-5), Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: R E
authors.initials: RE
authors.lastname: Dunin-Borkowski
authors.affiliation: Peter Grünberg Institute 9 (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: B E
authors.initials: BE
authors.lastname: Kardynal