Exciton optics, dynamics and transport in atomically thin semiconductors.

Monolayer transition metal dichalcogenides (TMDs) and related van der Waals heterostructures exhibit a rich exciton physics including bright and a variety of dark states as well as spatially separated interlayer excitons.

Solving 2D material Bloch equations for excitons, phonons and photons, we obtain a microscopic access to the interplay of optics, ultrafast dynamics and transport of excitons in these technologically promising materials.

In joint theory-experiment studies, we shed light on the importance of dark excitons on (i) low-temperature photoluminescence spectra of TMD monolayers and twisted homobilayers, (ii) temperature dependent exciton-exciton annihilation processes, (iii) ultrafast charge transfer dynamics in TMD heterostructures, (iv) exciton funneling in strained TMD monolayers as well as (v) anomalous exciton transport in TMD bilayers.

The gained microscopic insights into the spatiotemporal exciton dynamics are crucial for understanding and controlling many-particle phenomena governing exciton optics, dynamics and transport in technologically promising 2D materials and related heterostructures.