Ab-Initio Vibro-Polaritonic Spectra in Strongly Coupled Cavity-Molecule Systems

TL;DR

This paper introduces an ab-initio method to calculate vibro-polaritonic IR spectra in strongly coupled cavity-molecule systems, enabling detailed analysis and potential optimization of hybrid light-matter states.

Contribution

The authors develop a cavity Born-Oppenheimer Hartree-Fock approach tailored for molecular ensembles, advancing the computational tools for vibro-polaritonic spectra analysis.

Findings

Semi-classical approach accurately reproduces quantum spectra features

Method enables analysis of hybrid vibrational-photon states

Analytic gradients facilitate system optimization and dynamics simulations

Abstract

Recent experiments have revealed the profound effect of strong light-matter interactions in optical cavities on the electronic ground state of molecular systems. This phenomenon, known as vibrational strong coupling (VSC), can modify reaction rates and induce the formation of molecular vibrational polaritons, hybrid states involving both photon modes and vibrational modes of molecules. We present an ab-initio methodology, based on the cavity Born-Oppenheimer Hartree-Fock ansatz, which is specifically powerful for ensembles of molecules, to calculate vibro-polaritonic IR spectra. This method allows a comprehensive analysis of these hybrid states. Our semi-classical approach, validated against full quantum simulations, reproduces key features of the vibro-polaritonic spectra. The underlying analytic gradients also pave the way for optimizing cavity-coupled molecular systems and performing semi-classical dynamics simulations