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O: Fachverband Oberflächenphysik
O 7: Focus Session Ultrafast Electron Microscopy at the Space-Time Limit I
O 7.6: Vortrag
Montag, 17. März 2025, 12:00–12:15, H11
Dark field photoelectron momentum microscopy of electric field gated 2D semiconductors — •Jan Philipp Bange1, Bent van Wingerden1, Jonas Pöhls1, Wiebke Bennecke1, Paul Werner1, David Schmitt1, AbdulAziz AlMutairi3, Daniel Steil1, R. Thomas Weitz1, G. S. Matthijs Jansen1, Stephan Hofmann3, Giuseppe Meneghini2, Samuel Brem2, Ermin Malic2, Marcel Reutzel1, and Stefan Mathias1 — 1Georg-August-Universität Göttingen, Germany — 2Philipps-Universität Marburg, Germany — 3University of Cambridge, U.K.
A possibility to tune many-body interactions in two-dimensional semiconductors is in-situ electric field gating, which allows precise and reversible control of the filling of states in a moiré potential. In combination with ARPES for static band structure measurements, this approach has been shown to be a powerful experimental probe [1]. However, the study of excited states in gated 2D material structures, such as interlayer excitons [2] and trions, has so far remained elusive.
Here we combine time-resolved momentum microscopy with dark field imaging techniques to gain access to many-body interactions on femtosecond time and nanometer lengthscales [3]. We use this method to study electric field gated homobilayer WSe2 and report the ultrafast formation of quasiparticles as a function of applied gate voltage.
[1] Nguyen et al., Nature 572, 220 (2019).
[2] Bange et al., Science Advances 10, eadi1323 (2024).
[3] Schmitt et al., Nature Photonics, in press, arXiv.2305.18908.
Keywords: Momentum microscopy; Exciton; Gating; Ultrafast dynamics; Dark field imaging