Cavity Born-Oppenheimer approximation for molecules and materials via electric field response

Area of Science:

• Quantum Chemistry
• Materials Science
• Spectroscopy

Background:

• Cavity quantum electrodynamics studies light-matter interactions.
• Vibro-polaritons and phonon-polaritons are crucial for understanding quantum phenomena in confined systems.
• Accurate computation of these spectra is essential for designing novel materials and devices.

Purpose of the Study:

• To present a novel ab initio method for calculating vibro-polariton and phonon-polariton spectra.
• To enable efficient computation across a range of cavity parameters without repeated electronic structure calculations.
• To facilitate interpretation of results in terms of well-established molecular properties.

Main Methods:

• Development of an ab initio method based on the cavity Born-Oppenheimer approximation.
• Utilizing density functional perturbation theory to compute matter response to electric fields and nuclear displacements.
• Calculating Γ-point phonon-polariton spectra for 2D insulators using electric field response properties.

Main Results:

• The method expresses spectra using readily available quantities from standard density functional perturbation theory.
• Efficient computation of spectra for varying cavity parameters is achieved without additional electronic structure calculations.
• Demonstrated applicability to cavity-coupled molecular systems and 2D insulators.

Conclusions:

• The presented method offers an efficient and interpretable approach to computing vibro-polariton and phonon-polariton spectra.
• It bridges the gap between theoretical calculations and experimental observations in cavity quantum systems.
• The framework is versatile, applicable to both molecular and solid-state systems, including 2D materials.