Regensburg 2022 – scientific programme
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O: Fachverband Oberflächenphysik
O 81: 2D Materials 4: Heterostructures
O 81.3: Talk
Friday, September 9, 2022, 11:00–11:15, S052
Quantum spin Hall edge states and interlayer coupling in twisted bilayer WTe2 — •Felix Lüpke1, Dacen Waters2, Anh Pham3, Jiaqiang Yan4, David G. Mandrus5, Panchapakesan Ganesh3, and Benjamin M. Hunt6 — 1Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany — 2Physics, University of Washington — 3Center for Nanophase Materials Sciences, Oak Ridge National Lab — 4Materials Science and Technology Division, Oak Ridge National Lab — 5Department of Materials Science and Engineering, University of Tennessee — 6Physics, Carnegie Mellon University
The quantum spin Hall (QSH) effect, characterized by topologically protected spin-polarized edge states, was recently demonstrated in monolayers of the transition metal dichalcogenide (TMD) WTe2. However, the robustness of this topological protection remains largely unexplored in van der Waals heterostructures containing one or more layers of a QSH insulator. In this work, we use scanning tunneling microscopy and spectroscopy (STM/STS), to study twisted bilayer (tBL) WTe2 and compare it to topologically trivial natural bilayer. By comparing our experimental observations to first principles calculations, we conclude that the twisted bilayers are weakly coupled, preserving the QSH states and preventing back scattering.