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arXiv · 2501.12966

Coherent Interaction of 2s and 1s Exciton States in Transition-Metal Dichalcogenide Monolayers

Max Wegerhoff·Moritz Scharfstädt·Stefan Linden·Andrea Bergschneider
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Abstract

We use femtosecond pump-probe spectroscopy to study the coherent interaction of excited exciton states in WSe2 and MoSe2 monolayers via the optical Stark effect. For co-circularly polarized pump and probe, we measure a blueshift which points to a repulsive interaction between the 2s and 1s exciton states. The determined 2s-1s interaction strength is on par with that of the 1s-1s, in agreement with the semiconductor Bloch equations. Furthermore, we demonstrate the existence of a 2s-1s biexciton bound state in the cross-circular configuration in both materials and determine their binding energy.

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Max Wegerhoff, Moritz Scharfstädt, Stefan Linden, Andrea Bergschneider. 2025-01-22. Coherent Interaction of 2s and 1s Exciton States in Transition-Metal Dichalcogenide Monolayers. https://arxiv.org/abs/2501.12966

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