Regensburg 2025 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 53: 2D Semiconductors and van der Waals Heterostructures V
HL 53.2: Vortrag
Donnerstag, 20. März 2025, 15:15–15:30, H15
Collective charge excitations between moiré minibands in twisted WSe2 bilayers probed with resonant inelastic light scattering — •Hendrik Lambers1, Nihit Saigal1,2, Nicolai-Leonid Bathen1, Veljko Antić1, Lennart Klebl3, Dante M. Kennes4, Tim O. Wehling3, and Ursula Wurstbauer1 — 1Institute of Physics, University of Münster, Germany — 2EMBL Imaging Centre, Heidelberg, Germany — 3Institute of Theoretical Physics, University of Hamburg, Germany — 4Institute for Theory of Statistical Physics, RWTH Aachen University, Germany
The weak van der Waals coupling between monolayers of transitionmetal dichalcogenides (TMDCs) allows the realization of twisted van der Waals structures resulting in precisely tailored 2D quantum systems with superimposed moiré superlattice structures. These are dependent on twist angle and lattice constant mismatch and can cause flat moiré mini bands in the reduced Brillouin zone of the superlattice. Here we study these moiré minibands in tWSe2 homobilayers encapsulated in hBN by low temperature resonant inelastic light scattering (RILS) [1]. Guided by theoretical predications, we identify single particle-like collective inter moiré miniband excitations. Thereby, we establish RILS as a tool to quantitatively probe the formation of moiré minibands. Furthermore, we identify local twist angle variations by lateral force microscopy and correlate these findings with optical (Raman) spectroscopy. [1] N. Saigal et al., Phys. Rev. Lett. 133, 046902 (2024).
Keywords: TMDC homobilayer; moiré structure; collective excitation; resonant inelastic light scattering