Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 55: Graphene and 2D Materials (joint session TT/HL)
HL 55.9: Vortrag
Donnerstag, 20. März 2025, 17:15–17:30, H33
Dirac meets flat bands: Topological Mottness swap over through hybridization control — Siheon Ryee1, •Niklas Witt2,1,3, Lennart Klebl2,1, Jennifer Cano4,5, Giorgio Sangiovanni2, and Tim Wehling1,3 — 1Universität Hamburg — 2JMU Würzburg — 3Hamburg Centre for Ultrafast Imaging — 4Stony Brook University — 5CCQ
Graphene-based multilayer systems provide a versatile platform to explore the interplay between correlation physics and topology. These systems’ unique electronic properties arise from their low-energy bands, characterized by significant Berry curvature originating from graphene’s Dirac bands, which is believed to play a crucial role in stabilizing emergent correlated states such as superconducting order and various pseudomagnetic states. In this work, we investigate single-site functionalized graphene, where the Dirac bands hybridize with a correlated flat band of localized orbitals. Our findings based on dynamical mean-field theory (DMFT) calculations reveal a hybridization-driven transition between two symmetry-distinct Mott insulators with a protected metallic state emerging in between. Density functional theory (DFT) calculations suggest that the topological transition observed in our model system is achievable in real materials, specifically through the proximity coupling of epitaxial graphene on SiC with group IV intercalants. Unlike phenomena in other correlated graphene-based platforms, such as twisted bilayer graphene and rhombohedral graphene multilayers, the topology-enforced Mottness swap over occurs at a much higher energy scale of electron-volts.
Keywords: Mott insulator; electron correlation; topology; quantum geometry; Green function zero