A mixed perturbative-nonperturbative treatment for strong light-matter interactions

Area of Science:

• Quantum optics
• Nanophotonics
• Condensed matter physics

Background:

• Quantum emitter interaction with electromagnetic environments is crucial.
• Spectral density fully encodes this interaction information.
• Existing models often struggle with arbitrary coupling regimes.

Purpose of the Study:

• To present a novel framework for describing quantum emitter-environment interactions.
• To provide a Lindblad-like master equation applicable to any coupling regime.
• To handle general nanophotonic structures.

Main Methods:

• Splitting the spectral density into non-Markovian (strong coupling) and Markovian (weak coupling) parts.
• Nonperturbative treatment of strong coupling using discrete modes fitted to the spectral density.
• Perturbative treatment of weak coupling under Markovian approximation.

Main Results:

• A versatile master equation applicable to diverse coupling regimes.
• Accurate modeling of quantum emitter dynamics in general nanophotonic environments.
• Demonstrated validity through numerical simulations in various setups, including ultra-strong coupling.

Conclusions:

• The proposed framework offers a powerful and general approach to quantum emitter-environment interactions.
• It successfully models dynamics across weak, strong, and ultra-strong coupling regimes.
• This method provides a robust tool for nanophotonic system design and analysis.