title: Exploring three-dimensional orbital imaging with energy-dependent photoemission tomography.
abstract: Recently, it has been shown that experimental data from angle-resolved photoemission spectroscopy on oriented molecular films can be utilized to retrieve real-space images of molecular orbitals in two dimensions. Here, we extend this orbital tomography technique by performing photoemission initial state scans as a function of photon energy on the example of the brickwall monolayer of 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) on Ag(110). The overall dependence of the photocurrent on the photon energy can be well accounted for by assuming a plane wave for the final state. However, the experimental data, both for the highest occupied and the lowest unoccupied molecular orbital of PTCDA, exhibits an additional modulation attributed to final state scattering effects. Nevertheless, as these effects beyond a plane wave final state are comparably small, we are able, with extrapolations beyond the attainable photon energy range, to reconstruct three-dimensional images for both orbitals in agreement with calculations for the adsorbed molecule.
authors.affiliation: Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany.|Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Weiß
authors.affiliation: Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: D
authors.identifier: http://orcid.org/0000-0001-8883-0495
authors.initials: D
authors.lastname: Lüftner
authors.affiliation: Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: T
authors.initials: T
authors.lastname: Ules
authors.affiliation: Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: E M
authors.initials: EM
authors.lastname: Reinisch
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Kaser
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gottwald
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Richter
authors.affiliation: Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany.|Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Soubatch
authors.affiliation: Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Koller
authors.affiliation: Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: M G
authors.initials: MG
authors.lastname: Ramsey
authors.affiliation: Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany.|Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany.
authors.forename: F S
authors.initials: FS
authors.lastname: Tautz
authors.affiliation: Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Puschnig