Selective excitation of molecular vibrations via a two-mode cavity Raman scheme

Abstract

The experimental realization of strong light–matter coupling with molecules initiated the rapidly evolving field of molecular polaritonics. Most studies focus on how exciton polaritons, which combine electronic excitations with confined light modes, alter photochemistry. In this paper, we investigate their use in selectively exciting molecular vibrational states in the ground state. Selectively exciting molecules to high vibrational states with infrared lasers to catalyze ground-state chemical reactions is a challenging task. Here, we propose a two-cavity mode setup in the electronic strong coupling regime inspired by the process of stimulated Raman adiabatic passage to selectively populate excited vibrational states. One cavity mode actively pumps the molecular system, while the other provides a highly effective and tunable decay channel via photon leakage. We demonstrate the ability to selectively populate vibrational states for coherent and incoherent light sources using a molecular model system. Our initial findings show high efficiency and suggest a possible route to steering and controlling chemical reactions in the electronic ground state based on electronic strong coupling.