Highly nonlinear dipolar exciton-polaritons in bilayer MoS₂

Area of Science:

• Solid-state physics
• Quantum optics
• Materials science

Background:

• Achieving nonlinear optical response at low photon densities in solids is challenging.
• Exciton-polaritons in semiconductor microcavities are promising but suffer from weak interactions.
• Dipolar excitons offer stronger interactions but typically have weak oscillator strength.

Purpose of the Study:

• To demonstrate enhanced nonlinear optical interactions using dipolar exciton polaritons.
• To investigate the potential of bilayer MoS2 for strong light-matter interactions.
• To overcome the limitations of weak quasiparticle interactions in solid-state nonlinear optics.

Main Methods:

• Formation of interlayer dipolar excitons in homobilayer MoS2 through hybridization.
• Coupling of these dipolar excitons with cavity photons to form dipolar exciton polaritons.
• Measurement of nonlinear optical response and comparison with conventional excitons.

Main Results:

• Demonstrated the formation of dipolar exciton polaritons in bilayer MoS2.
• Observed unprecedented nonlinear interaction strengths.
• Achieved a ten-fold increase in nonlinearity for interlayer dipolar excitons compared to A excitons.

Conclusions:

• Interlayer dipolar excitons in bilayer MoS2 provide a viable route to strong nonlinear optical responses.
• These highly nonlinear dipolar polaritons are promising for future solid-state quantum nonlinear devices.
• The hybridization mechanism effectively enhances oscillator strength, overcoming previous limitations.