Toward Collective Chemistry under Strong Light-Matter Coupling.

Area of Science:

• Quantum optics
• Condensed matter physics
• Physical chemistry

Background:

• Collective strong light-matter coupling enables control over molecular and material properties.
• Understanding polaritonic dynamics is challenging due to the large number of interacting molecules.

Purpose of the Study:

• To develop a many-body theory for investigating spectroscopy and dynamics in the collective strong coupling regime.
• To analyze the behavior of molecular ensembles within optical cavities.

Main Methods:

• A pseudoparticle representation of the molecular Hamiltonian was employed.
• The polaritonic Hamiltonian was mapped to a coupled fermion-boson model.
• Nonequilibrium Green's function theory with a large N expansion was used for analysis.

Main Results:

• A macroscopic cavity field is necessary for collective effects in the thermodynamic limit.
• The developed theory accurately describes the driven Tavis-Cummings model.
• Numerical results show excellent agreement with exact solutions.

Conclusions:

• The many-body theory provides a robust framework for studying collective polaritonic phenomena.
• The findings highlight the critical role of the cavity field in achieving collective effects.
• This work advances the understanding of light-matter interactions in quantum systems.