Cavity Control of Excitons in Two-Dimensional Materials

Area of Science:

• Condensed Matter Physics
• Quantum Optics
• Materials Science

Background:

• Two-dimensional (2D) materials and van der Waals (vdW) heterostructures exhibit unique optical properties.
• Excitons, bound electron-hole pairs, are crucial for these optical phenomena.
• Controlling exciton behavior is key to developing novel optoelectronic devices.

Purpose of the Study:

• To propose a method for controlling the optical spectra of 2D materials and vdW heterostructures.
• To investigate the formation and properties of exciton-polaritons via quantum cavity embedding.
• To explore the influence of the dielectric environment on light-matter coupling.

Main Methods:

• Utilizing a novel nonperturbative many-body framework.
• Solving the coupled electron-photon Schrödinger equation within a quantum-electrodynamical extension of the Bethe-Salpeter approach.
• Applying a simplified Mott-Wannier description for large vdW heterostructures and encapsulated 2D materials.

Main Results:

• Demonstrated reordering and mixing of bright and dark exciton spectral features.
• Observed inversion of intra- and interlayer excitonic resonances in type II vdW heterostructures.
• Showed strong dependence of cavity light-matter coupling on the dielectric environment, controllable via encapsulation.

Conclusions:

• Quantum cavity embedding offers a robust and efficient route to control optical spectra in 2D materials and vdW heterostructures.
• The developed theoretical framework enables ab initio simulations of exciton-polaritons across various coupling regimes.
• The findings provide a pathway for designing advanced quantum optical devices based on 2D materials.