Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 11: Focus Session: Spins on Surfaces studied by Atomic Scale Spectroscopies II
O 11.9: Vortrag
Montag, 18. März 2024, 17:15–17:30, MA 004
Distinct Quantum States in Topological Insulator Surfaces of Nanowires and Nanoribbons of Bismuth Selenide — •Christian Nweze1, Tomke Eva Glier1, Mika Rerrer1, Malte van Heek1, Sarah Scheitz1, Lewis Akinsinde1, Niklas Kohlmann2, Lorenz Kienle2, Yalan Huang1, Wolfgang Parak1, Nils Huse1, and Michael Rübhausen1 — 1Institute of Nanostructure and Solid-State Physics, University of Hamburg, Hamburg, 22761, Germany. — 2Institute for Materials Science, Faculty of Engineering, Kiel University, Kaiserstrasse 2, 24143, Kiel, Germany
Topological insulators (TIs) exhibit unconventional quantum phases that can be manipulated with external quantum confinements. The geometry of the surface of 3D TIs plays a crucial role in tuning the quantum confinement in TIs. For instance, morphing a 3D TI into a 1D cylinder results into a curved surface in which the electron spin is locked perpendicular to the momentum and, as well as, tangential to the perimeter of the TI nanowire. This leads to a new state with a Spin-Berry Phase (SBP). We utilized Surface-Enhanced Raman Scattering (SERS) as sensor to study the confinement of quasi-relativistic electrons in TI nanowires. Our result shows diameter-dependent SERS in nanowires which is attributed to the self-interference effect of the electronic wavefunction along the curved surface of the nanowires. Rectangular shaped Nanoribbons do not show this effect. Plasmonic gold nanoparticles attached at the distinct topological surface states enables us to discriminate different subband splitting between nanowires and nanoribbons.
Keywords: topological insulator; spin berry phase; quantum confinement; nanowire; nanoribbon