Speaker
Description
Excitons - quasiparticles formed by coulomb-bounded electron-hole pairs, play a critical role in the optical response of 2D semiconductors. In monolayer Transition Metal Dichalcogenides (TMDCs) – prototypical 2D semiconductors, the interplay of spin and valley degrees of freedom gives rise to a complex excitonic landscape with significant contributions from the dark excitons which are hidden from the conventional optical spectroscopy. Meanwhile, time- and angle- resolved photoemission spectroscopy (TR-ARPES) has emerged as a powerful technique to study excitons in energy-momentum space [1,2]. In this talk, I will present the recent advances in resolving fine dark excitonic states in 2D semiconductors, elucidating the holistic ultrafast dynamics involving their spin-valley configurations, thereby providing a more comprehensive understanding of fundamental properties. Furthermore, I will discuss their potential for applications and for engineering the exotic nonequilibrium states in semiconductors [3,4].
Reference:
[1] Science Advances 7, eabg0192 (2021).
[2] Nature 603, 7900 (2022).
[3] Nat Commun 16, 6385 (2025).
[4] arXiv:2403.08725.
| Session Selection | Condensed Matter |
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