  Integrating two-dimensional van der Waals materials with optical cavities has
revealed a fascinating platform to study exciton-polariton physics.
Manipulating exciton polaritons often requires external control over the
electrical and optical properties of materials. Here we demonstrate the
electrical control of 2D exciton polaritons by strongly coupling a transition
metal dichalcogenides (TMD) heterostructure to a photonic crystal nanocavity.
Through precise control of the doping level in the TMD monolayers using
electrostatic gating, we demonstrate a wide range of tunability in the exciton
oscillator strength and hence the exciton photon hybridization. This tunability
leads to the demonstration of a continuous transition from weak to strong
coupling regime, as manifested by the disappearance and emergence of exciton
polaritons, showcasing the versatility of our approach. Our work paves the way
to further exploring nonlinear and quantum exciton polaritons in 2D materials
and their device applications.
