Ultrafast Investigation of the Strong Coupling System between Square Ag Nanohole Array and Monolayer WS₂

Area of Science:

• Optics and Photonics
• Quantum Information Science
• Materials Science

Background:

• Strong coupling between light and matter is crucial for advanced optical devices.
• Two-dimensional materials like WS₂ offer unique light-matter interaction properties.
• Exciton-polaritons formed via this coupling are key for quantum phenomena.

Purpose of the Study:

• To investigate the strong coupling between Bloch-surface plasmon polaritons and WS₂ excitons.
• To quantify the Rabi splitting and analyze the polariton decay dynamics.
• To explore potential applications in quantum information and nanophotonics.

Main Methods:

• Angle-resolved transient absorption spectroscopy was employed.
• A square silver nanohole array was used to generate Bloch-surface plasmon polaritons.
• Monolayer WS₂ was utilized to host the A exciton.

Main Results:

• A significant Rabi splitting of 74 meV was achieved, confirming strong coupling.
• Analysis of polariton damping revealed faster decay in the lower branch compared to the upper branch.
• The study demonstrates efficient light-matter interaction in the studied system.

Conclusions:

• The findings deepen the understanding of exciton-polariton dynamics in 2D materials.
• This work highlights potential applications in Bose-Einstein condensation and quantum information processing.
• The demonstrated strong coupling paves the way for novel nanophotonic devices.