Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 12: HL Poster I

HL 12.30: Poster

Montag, 1. April 2019, 17:30–20:00, Poster E

Topological surface states in α -Sn: from 3D Dirac semimetal to quasi-2D few-layer stanene — •Victor A. Rogalev¹, Johannes Jehn¹, Felix Reis¹, Florian Adler¹, Maximilian Bauernfeind¹, Jonas Erhardt¹, Liam B. Duffy², Thorsten Hesjedal², Moritz Hoesch³, Gustav Bihlmayer⁴, Jörg Schäfer¹, and Ralph Claessen¹ — ¹Physikalisches Institut und Röntgen Center for Complex Materials Systems, Universität Würzburg, 97074 Würzburg, Germany — ²Clarendon Laboratory, Physics Department, Oxford University, OX1 3PU, United Kingdom — ³Diamond Light Source, Didcot, OX11 0DE, United Kingdom — ⁴Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich,52428 Jülich, Germany

We report on the TSS evolution in α -Sn films with different thickness and surface orientation, studied by angle-resolved photoemission. α -Sn films were grown epitaxially on InSb substrates (0.14% biaxial compressive strain) with (001)- and (111)-surface orientations, which renders a Dirac semimetal phase. For the (001)-oriented α -Sn films we observe quantum well effects in the electronic structure, while the Dirac point (DP) remains mainly unchanged down to ∼2.5 nm. The DP in (111)-oriented α -Sn was found to be 200 meV below the Fermi level for 10-nm-thick α -Sn film, which enabled us to observe the hybridization gap opening in TSS for lower α -Sn film thicknesses. The crossover to a quasi-2D few-layer stanene electronic structure is accompanied by a disappearance of the TSS spectral weight and a gap opening, in agreement with our DFT calculations of the electronic bandstructure.