SKM 2023 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 16: Nanostructures at Surfaces (joint session O/CPP)
CPP 16.5: Talk
Monday, March 27, 2023, 16:00–16:15, GER 39
Giant confinement of surface electrons in a two-dimensional metal-organic porous network — •Lu Lyu1, Tobias Eul1, Wei Yao1, Zakaria M. Abd El-Fattah2, Mostafa Ashoush2, Ignacio Piquero-Zulaica3, Johannes V. Barth3, Martin Aeschlimann1, and Benjamin Stadtmüller1,4 — 1Department of Physics, University of Kaiserslautern, Germany. — 2Physics Department, Faculty of Science, Al-Azhar University, Egypt. — 3Physics Department E20, Technical University of Munich, Germany — 4Institute of Physics, Johannes Gutenberg University Mainz, Germany.
Two-dimensional metal-organic porous networks (2D-MOPNs) are highly flexible nano-architectures for exploring the quantum confinement of surface electrons on noble metals. So far, 2D-MOPNs have been predominantly studied for the confinement of occupied Shockley-type surface states (SS). In contrast, the confinement of excited surface states, such as image potential states (IPSs), remains elusive. In this work, we apply two-photon photoemission to investigate the band dispersion of the first image-potential state (n = 1 IPS) in a Cu-T4PT nanoporous network on Cu(111). We find the formation of a Bloch-like band structure with a substantially increased effective band mass of the IPS (> 150 %). In contrast, the effective band mass of the SS remains almost unchanged (< 3%). This band renormalization of the IPS can be attributed to the spatial distribution of its charge density perpendicular to the surface, which reveals the highest density at the vertical adsorption position of the T4PT backbone. This coincidence is responsible for the giant confinement.