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O: Fachverband Oberflächenphysik
O 56: 2D Materials beyond Graphene
O 56.3: Poster
Dienstag, 21. März 2017, 18:30–20:30, P2-EG
Synthesis and Spectroscopy of Bismuthene — •Felix Reis1, Gang Li2,3, Lenart Dudy1, Maximilian Bauernfeind1, Stefan Glass1, Werner Hanke3, Ronny Thomale3, Jörg Schäfer1, and Ralph Claessen1 — 1Physikalisches Institut and RCCM, Universität Würzburg, Würzburg, Germany — 2Institute for Solid State Physics, Vienna University of Technology, Vienna, Austra — 3Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Würzburg, Germany
The search for quantum spin Hall materials with large band gap has become one of the major research thrusts of solid state physics. Despite other approaches, graphene with its honeycomb lattice geometry always fascinated the community. Here, we report the realization of so-called ”bismuthene“, which is synthesized on the wide-bandgap substrate SiC(0001). Scanning tunneling microscopy imaging clearly displays the honeycomb structure. Using tunneling spectroscopy, we find a huge bulk gap of ∼ 800 meV, with the Fermi level positioned well inside this gap. Interestingly, metallic edge states are observed when the bismuthene film edge is approached. A comparison of angle-resolved photoemission measurements and density functional theory band structure calculations is a further manifestation of the formation of bismuthene. To understand the empirical electronic properties, a detailed theoretical analysis is performed. A low-energy effective model demonstrates that the substrate not only stabilizes bismuthene, but plays a crucial role in the formation of the observed huge band gap, which is driven by the large on-site spin-orbit coupling.