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O: Fachverband Oberflächenphysik
O 40: Poster: Topological Materials
O 40.3: Poster
Tuesday, March 19, 2024, 18:00–20:00, Poster D
On the Edge State of Finite 2D Bi2Se3 Crystals — •Auke Vlasblom, Victor Wesselingh, Jesper Moes, Jara Vliem, Daniel Vanmaekelbergh, and Ingmar Swart — Utrecht University, Utrecht, The Netherlands
Topological insulators in two or three dimensions exhibit an insulating bulk, but possess gapless conducting edge or surface states that are protected by time-reversal symmetry. One property of the surface/edge state is spin momentum locking, which results in two types of surface currents, each with opposite spin (up or down) and opposite momentum (direction). In the 2D regime, top and bottom states hybridize and the interior becomes insulating. The two remaining types of edge currents are fully protected from backscattering by non-magnetic impurities.
Here, we study thin (3–6 quintuple layers) finite sized Bi2Se3 crystals, prepared via wet-chemical synthesis, using scanning tunneling microscopy and spectroscopy. Measurements are performed on Bi2Se3 nanoplatelets with varying thickness to study the transition between 3D and 2D topological insulators. Additionally, the robustness of the edge states is investigated with respect to structural defects and deposition of magnetic impurities.
Keywords: Scanning tunneling microscopy; Topological insulator; Bismuth selenide