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arXiv · 2405.17099

Element-specific ultrafast lattice dynamics in monolayer WSe2

H. Jung·S. Dong·D. Zahn·T. Vasileiadis·H. Seiler·R. Schneider·S. Michaelis de Vasconcellos·V. C. A. Taylor·R. Bratschitsch·R. Ernstorfer·Y. W. Windsor
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Abstract

We study monolayer WSe2 using ultrafast electron diffraction. We introduce an approach to quantitatively extract atomic-site-specific information, providing an element-specific view of incoherent atomic vibrations following femtosecond excitation. Via differences between W and Se vibrations, we identify stages in the nonthermal evolution of the lattice. Combined with a calculated phonon dispersion, this element specificity enables us to identify a long-lasting overpopulation of specific optical phonons, and to interpret the stages as energy transfer processes between specific phonon groups. These results demonstrate the appeal of resolving element-specific vibrational information in the ultrafast time domain.

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H. Jung, S. Dong, D. Zahn, T. Vasileiadis, H. Seiler, R. Schneider, S. Michaelis de Vasconcellos, V. C. A. Taylor, R. Bratschitsch, R. Ernstorfer, Y. W. Windsor. 2024-05-27. Element-specific ultrafast lattice dynamics in monolayer WSe2. https://doi.org/10.1021/acs.nanolett.4c03611

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