Dresden 2026 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 54: Graphene: Electronic structure, excitations, etc. (joint session O/TT)
TT 54.8: Vortrag
Mittwoch, 11. März 2026, 16:45–17:00, HSZ/0204
Doping monolayer graphene to the Van Hove singularity — •Guangyao Miao1, Daniel Jansen1, Bilal Hawashin2, Julian Kleeschulte2, Katharina Offermann1, Christian Krämer1, Affan Safeer1, Abdallah Karaka1, Jeison Fischer1, Thomas Michely1, Michael M. Scherer2, and Wouter Jolie1 — 1II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Cologne, Germany — 2Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum, Germany
Tuning correlated states in graphene is an intriguing topic, particularly since the experimental realization of superconductivity, correlated insulator states, and magnetic states in twisted-angle bilayer graphene near the magic angle, along with Van Hove singularities (VHSs) tuned to the Fermi level. Such correlated phenomena have also been predicted in monolayer graphene doped to its van Hove singularity. Motivated by this, we study the effect of Cs doping on a graphene monolayer on Ir(111) using MBE. A √3×√3 superstructure is observed due to the Cs intercalations between graphene and Ir(111). Further deposition of Cs on top of graphene leads to the formation of several surface structures with varying Cs concentrations, including adatoms, stripes, and compact islands. Their morphology and electronic structures are revealed by scanning tunneling microscopy and spectroscopy at low temperature. By optimizing the dosage, we successfully tune the VHS to the vicinity of the Fermi level and observe a 2√3×2√3 superstructure with respect to the graphene lattice. Possible origins of the superstructure related to many-body interactions will be discussed.
Keywords: graphene; doping; Van Hove singularity; flat band; STM