Dresden 2026 – scientific programme
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O: Fachverband Oberflächenphysik
O 14: Ultrafast electron dynamics at surface and interfaces I
O 14.2: Talk
Monday, March 9, 2026, 15:30–15:45, TRE/MATH
Disentangling exciton resonances in 2D materials by time-resolved XUV-ARPES — •Gregor Zinke1,2, Antonius Naujok1, Franz Spartz1, Sebastian Hedwig1, Tobias Eul2, Martin Aeschlimann1, and Benjamin Stadtmüller2 — 1Department of Physics and Research Center OPTIMAS, RPTU University Kaiserslautern - Landau, 67663 Kaiserslautern, Germany — 2Experimental Physics II, Institute for Physics, University of Augsburg, 86159 Augsburg
Ultrafast and coherent electron dynamics in 2D materials and their heterostructures are governed by the complex energy landscape of various excitons. These quasi-particles are often separated only by tens of meV, making them difficult to distinguish in conventional time-resolved experiments due to the spectral linewidth of ultrashort pulses. Although interferometric photoemission experiments have shown potential in resolving (coherent) excitation pathways and absorption resonances, they depend mostly on optical pulses, limiting the observable momentum space, leaving high-symmetry points of 2D materials inaccessible. To address these limitations, we present a modified version of interferometric trARPES that employs two active, phase-stabilized IR pump pulses and a fs-XUV probe pulse for photoionization. We demonstrate the capability of our approach by examining the well-known A-exciton transition energies in WSe2 at different frequencies of our pump spectrum, showing how temporal Fourier analysis of the entire ARPES spectrum allows linking distinct transition energies to congruent excitation paths within the WSe2 electronic band structure.
Keywords: WSe2; photoemission; ultrafast; TMDC; exciton