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O: Fachverband Oberflächenphysik

O 36: Poster: Ultrafast Electron Dynamics at Surfaces and Interfaces

O 36.1: Poster

Tuesday, March 19, 2024, 18:00–20:00, Poster C

Differences in the electron dynamics of inequivalent (001) surfaces of Td-WTe₂: top and bottom or topological trivial and topological non-trivial? — •Klaas Opitz¹, Hauke Beyer¹, Eduard Moos¹, Kai Rossnagel^1,2,3, and Michael Bauer^1,2 — ¹Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany — ²Kiel Nano, Surface and Interface Science KiNSIS, Kiel University, 24118 Kiel, Germany — ³Deutsches Elektronen-Synchrotron DESY, Ruprecht Haensel Lab, 22607 Hamburg, Germany

ARPES spectra of [100]-oriented Td-WTe₂ show clear differences, which in the past have been associated either with different topological phases [1] or alternatively interpreted as a signature for the small but finite structural differences of the (001) and (001) surface resulting from the broken inversion symmetry of the material [2]. In this contribution we will present time-resolved ARPES data of Td-WTe₂ that clearly hint to distinct differences also in the electron dynamics for these two surfaces. We will discuss our results under consideration of the different interpretations of the ARPES data.

[1] Y. Wu et al., Phys. Rev. B. 94, 121113(R) (2016).

[2] Y. Wan et al., Phys. Rev. B. 105, 085421 (2022).

Keywords: ultrafast; TMDC; WTe2; Weyl-Semimetal; trARPES