Excited-state vibration-polariton transitions and dynamics in nitroprusside

Abstract

Strong cavity coupling to molecular vibrations creates vibration-polaritons capable of modifying chemical reaction kinetics, product branching ratios, and charge transfer equilibria. However, the mechanisms impacting these molecular processes remain elusive. Furthermore, even basic elements determining the spectral properties of polaritons, such as selection rules, transition moments, and lifetimes are poorly understood. Here, we use two-dimensional infrared and filtered pump–probe spectroscopy to report clear spectroscopic signatures and relaxation dynamics of excited vibration-polaritons formed from the cavity-coupled NO band of nitroprusside. We apply an extended multi-level quantum Rabi model that predicts transition frequencies and strengths that agree well with our experiment. Notably, the polariton features decay ~3–4 times slower than the polariton dephasing time, indicating that they support incoherent population, a consequence of their partial matter character.

Collective Vibrational Strong Coupling Effects on Molecular Vibrational Relaxation and Energy Transfer: Numerical Insights via Cavity Molecular Dynamics Simulations**

“…A recent experimental work [24] shows that the observed vibrational relaxation rate of the “dark reservoir” (or the hot molecules) is not modified in a Fabry–Pérot microcavity (where the molecular number can reach 10 9 ∼10 12 ), which is consistent with our simulation results. For plasmonic cavities—an emerging platform for studying VSC, [25, 26] since the effective cavity volume is much less than Fabry–Pérot microcavities, the slower‐than‐ O (1/ N sub ) scaling could be observed in experiments.…”

Collective Vibrational Strong Coupling Effects on Molecular Vibrational Relaxation and Energy Transfer: Numerical Insights via Cavity Molecular Dynamics Simulations**

“…Ar ecent experimental work [24] shows that the observed vibrational relaxation rate of the "dark reservoir" (or the hot molecules) is not modified in aF abry-PØrot microcavity (where the molecular number can reach 10 9~1 0 12 ), which is consistent with our simulation results.F or plasmonic cavities-an emerging platform for studying VSC, [25,26] since the effective cavity volume is much less than Fabry-PØrot microcavities,t he slower-than-O(1/N sub )s caling could be observed in experiments.…”

Ultrafast modulation of vibrational polaritons for controlling the quantum field statistics at mid-infrared frequencies

“…The mechanism involves ultrafast modulation of the confined mid infrared vacuum field under strong and ultrastrong light-matter coupling. Strong vibration-cavity coupling has been demonstrated with Fabry-Perot cavities [17][18][19][20][21][22][23][24][25], plasmonic resonators [26,27], van der Waals resonators [28] and polar dielectric resonators [29]. Ultrastrong coupling [30,31] has also been demonstrated in the mid-infrared [32][33][34].…”