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PhOG Seminar

Christian Gebhardt, LMU München
Monolayers of Transition Metal Dichalcogenides Coupled to a Fiber-Microcavity

Atomically thin crystals of transition metal dichalcogenides have recently drawn attention due to their promising optoelectronic properties in the monolayer limit. The two-dimensional shape in combination with strong optical transitions has significant potential for optoelectronic devices. In our experiment, we use an open-access fiber-microcavity to investigate the strong coupling regime of excitons in WS₂ and the resonator mode. The fully tunable setup allows us to adjust the spatial separation of both cavity mirrors in three dimensions with a stable, micron-scale cavity mode and thus to vary the exciton-photon coupling in situ. Altering the cavity length in a first step, we reproducible observe polaritons in the strong coupling regime with a Rabi splitting energy above kBT and validate the characteristic cavity-length dependency of the coupling constant. In a second step, a new hyperspectral imaging technique enables two-dimensional polariton measurements, which spatially resolves significant variation of the Rabi splitting energy within one monolayer sheet. Those splitting fluctuations can be linked to variations in absorption and emission spectra.

Tuesday, 08.08.17

11:15 h - 12:15 h

Location: Raum 204

Amalienstr. 54