Electrically tuneable exciton energy exchange between spatially separated 2-dimensional semiconductors in a microcavity

Electrical control over the energy exchange between exciton states mediated by cavity-polaritons at room temperature is demonstrated. A field-effect device, based on a monolayer of WS2, is built on the bottom metallic mirror of a tuneable Fabry-Perot microcavity; on the top mirror, a monolayer of MoS2 is placed leaving a controllable gap of similar to 1 mu m between the top and bottom semiconductors. This device is specially designed for the multiple hybridization of microcavity modes with the two exciton species supported by WS2 and MoS2, allowing for polariton-mediated exciton energy exchange. It is further shown that the tuning of the free carrier density in the WS2 film through field-effect gating leads to strong modulation of the Rabi splitting that modifies the excitonic and photonic nature of exciton-polaritons. Electrical control of polaritonic devices may lead to technological applications using switchable quantum states.