Theory of Electronic Interface States in Weakly Bound Heterostructures

Summary

We aim at understanding electronic states at the interface between different semiconducting low-dimensional materials (e.g., molecular crystals or transition metal dichalcogenides) or between such materials and a (noble) metal. Employing a combination of density-functional theory, van der Waals interaction, and many-body perturbation theory, all relevant physical mechanisms (chemical bonds, physisorption, electrostatic interaction, dielectric screening, image-potential effects, etc.) are correctly included. Challenges are given by, e.g. the role of material thickness or the spatial decay of interface states in the normal direction. In the lateral dimension, dispersive bands as well as local, non-dispersive states may occur, depending on the competition between interaction within each material and hybridization across the interface.

Project-related publications

1. A. Haags, A. Reichmann, Q.T. Fan, L. Egger, H. Kirschner, T. Naumann, S. Werner, T. Vollgraff, J. Sundermeyer, L. Eschmann, X. Yang, D. Brandstetter, F.C. Bocquet, G. Koller, A. Gottwald, M. Richter, M. G. Ramsey, M. Rohlfing, P. Puschnig, J.M. Gottfried, S. Soubatch, F.S. Tautz
   Kekulene: On-Surface Synthesis, Orbital Structure, and Aromatic Stabilization
   ACS Nano 14, 15766 (2020).
2. T. Deilmann, P. Krüger, M. Rohlfing
   Ab initio studies of exciton g factors: Monolayer transition metal dichalcogenides in magnetic fields
   Phys. Rev. Lett. 124, 226402 (2020).
3. L. Eschmann, A. Sabitova, R. Temirov, F.S. Tautz, P. Krüger, M. Rohlfing
   Coveragedependent anisotropy of the NTCDA/Ag(111) interface state dispersion
   Phys. Rev. B 100, 125155 (2019).
4. I. Niehues, R. Schmidt, M. Drüppel, P. Marauhn, D. Christiansen, M. Selig, G. Berghäuser, D. Wigger, R. Schneider, L. Braasch, R. Koch, A. Castellanos-Gomez, T. Kuhn, A. Knorr, E. Malic, M. Rohlfing, S. Michaelis de Vasconcellos, R. Bratschitsch
   Strain Control of Exciton-Phonon Coupling in Atomically Thin Semiconductors
   Nano Lett. 18, 1751 (2018).