Dresden 2026 – scientific programme
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O: Fachverband Oberflächenphysik
O 74: Graphene: Electronic structure, excitations, etc. – Poster (joint session O/TT)
O 74.5: Poster
Wednesday, March 11, 2026, 18:00–20:00, P2
Terbium intercalation as a route to n-doping of graphene past the van Hove singularity — •Bharti Matta1, Philipp Rosenzweig1, Craig Polley2, Kathrin Küster1, and Ulrich Starke1 — 1Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany — 2MAX IV Laboratory, Lund, Sweden
Exotic ground states driven by many-body interactions, such as unconventional chiral superconductivity and spin-density waves, were theoretically predicted more than a decade ago for heavily n-doped graphene near the van Hove singularity (VHS). In recent years, achieving such high doping levels in epitaxial graphene on SiC via intercalation has attracted considerable interest. Intercalation of rare-earth elements such as Gd, Yb, and Er has already proven promising in reaching these regimes. Here, we demonstrate that intercalation of Tb atoms at the graphene/SiC interface provides access to extreme n-doping levels beyond the π* VHS, without requiring any adsorbates on the graphene surface. The extended VHS is shifted by 0.07 eV below the Fermi level (EF) as seen in angle-resolved photoemission spectroscopy. From the area enclosed by the giant hole pocket around Γ, we extract an electron density of ≈ 5×1014 cm−2. Strong renormalization of the graphene bands leads to a Dirac point about 1.55 eV below EF, indicating that the doping cannot be described by a rigid single-particle band shift. Based on these experimental parameters, theoretical calculations predict the emergence of topological superconductivity with a critical temperature up to 600 mK (S. A. Herrera et al., ACS Nano 18 (51), 34842–34857 (2024)).
Keywords: Epitaxial graphene on SiC; Tb intercalation; Band structure; ARPES; Doping beyond VHS