2D Electronic Spectroscopy Uncovers 2D Materials: Theoretical Study of Nanocavity-Integrated Monolayer Semiconductors.

Transition metal dichalcogenides (TMDs) have emerged as promising 2D semiconductors due to their strong excitonic effects, spin-valley coupling, and tunable light-matter interactions. Here, we employ a fully quantum, numerically "exact" multi-Davydov Ansatz approach to simulate two-dimensional electronic spectroscopy signals in hBN-encapsulated WSe2 monolayers integrated with a tunable nanocavity. By incorporating both momentum-bright and momentum-dark excitons alongside detailed phonon dispersion, our model captures vibrational resonances and exciton-polariton behaviors, enabling the evaluation of beating maps (3D spectra) that disentangle ground-state bleach and stimulated emission pathways. The results highlight the essential role of vibronic coherence in TMD monolayers and offer quantitative guidance for the design of next-generation optoelectronic devices based on cavity-coupled 2D materials.