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O: Fachverband Oberflächenphysik
O 49: Poster Session IV: Electronic structure of surfaces: Spectroscopy, surface states II
O 49.2: Poster
Tuesday, March 2, 2021, 13:30–15:30, P
Efficient orbital imaging using ToF momentum microscopy with a femtosecond HHG light source — •Wiebke Bennecke1, G. S. Matthijs Jansen1, David Schmitt1, Marius Keunecke1, Christina Möller1, Daniel Steil1, Russell Luke2, Sabine Steil1, and Stefan Mathias1 — 1I. Physikalisches Institut, Georg-August-Universität Göttingen — 2Institut für Numerische und Angewandte Mathematik, Georg-August-Universität Göttingen
Orbital imaging (OI) is a powerful method to visualize molecular orbitals in molecule-metal interfaces using angle-resolved photoemission spectroscopy (ARPES) data and phase retrieval algorithms. Here, we will report on our advances in both of these aspects.
So far, successful orbital imaging has been based on the support constraint, for which the shape of the orbital must be known and which can be difficult to estimate. We have developed a sparsity-driven approach to phase retrieval, which uses only the number of non-zero pixels in the orbital and is independent of the actual orbital shape. This algorithm has been applied successfully to both simulated and experimental static ARPES data of different organic molecules.
Our photoemission setup consists of a femtosecond high harmonic generation beamline and a time-of-flight momentum microscope which yields the full momentum- and energy-resolved photoelectron spectrum in a single measurement. This enables us to image multiple molecular orbitals simultaneously. Combined with the sparsity-driven phase retrieval, this setup provides the ideal platform for orbital imaging with great potential to move towards time-resolved measurements.