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O: Fachverband Oberflächenphysik
O 45: Ultrafast Electron Dynamics at Surfaces and Interfaces IV
O 45.5: Talk
Wednesday, March 20, 2024, 11:30–11:45, MA 041
Ultrafast nano-imaging of dark excitons — •David Schmitt1, Jan Philipp Bange1, Wiebke Bennecke1, Giuseppe Meneghini2, AbdulAziz AlMutairi3, Marco Merboldt1, Jonas Pöhls1, Sabine Steil1, Daniel Steil1, R. Thomas Weitz1, Stephan Hofmann3, Samuel Brem2, G. S. Matthijs Jansen1, Ermin Malic2, Stefan Mathias1, and Marcel Reutzel1 — 1Georg-August-Universität Göttingen, I. Physikalisches Institut, Germany — 2Fachbereich Physik, Philipps-Universität, Marburg, Germany — 3Department of Engineering, University of Cambridge, Cambridge CB3 0FA, U.K.
The optical response of transition-metal dichalchodgenide (TMDs) heterostructures is determined by the formation of tightly-bound electron-hole pairs, or so-called excitons. For the application of TMDs in optoelectronic devices it is necessary to understand not only the temporal evolution of the formation, thermalization and relaxation of excitons within energy- and momentum-space [1], but also the impact of spatial inhomogeneities to the exciton landscape and ultrafast dynamics on the relevant nanometer to micrometer spatial scale. In this talk, we will demonstrate how our novel method of ultrafast dark-field momentum microscopy [2] can be used to track the ultrafast formation dynamics of excitons with unparalleled simultaneous spatio-temporal and spatio-spectral information.
[1] Schmitt et al., Nature 608, 499-503 (2022)
[2] Schmitt et al., arXiv:2305.18908 (2023)
Keywords: Ultrafast momentum microscopy; trARPES; exciton dynamics; interlayer excitons; TMD heterostructures