Modified relaxation dynamics and coherent energy exchange in coupled vibration-cavity polaritons

• Published in: Nature communications 2016-11, Vol.7 (1), p.13504-13504, Article 13504
• Main Authors: Dunkelberger, A. D., Spann, B. T., Fears, K. P., Simpkins, B. S., Owrutsky, J. C.
• Format: Article
• Language: English
• Subjects: 140/125; 639/638/440/94; 639/638/440/948; Chemistry; Energy; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Vibration
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms13504

Coupling vibrational transitions to resonant optical modes creates vibrational polaritons shifted from the uncoupled molecular resonances and provides a convenient way to modify the energetics of molecular vibrations. This approach is a viable method to explore controlling chemical reactivity. In this work, we report pump–probe infrared spectroscopy of the cavity-coupled C–O stretching band of W(CO) 6 and the direct measurement of the lifetime of a vibration-cavity polariton. The upper polariton relaxes 10 times more quickly than the uncoupled vibrational mode. Tuning the polariton energy changes the polariton transient spectra and relaxation times. We also observe quantum beats, so-called vacuum Rabi oscillations, between the upper and lower vibration-cavity polaritons. In addition to establishing that coupling to an optical cavity modifies the energy-transfer dynamics of the coupled molecules, this work points out the possibility of systematic and predictive modification of the excited-state kinetics of vibration-cavity polariton systems. Vibration-cavity polaritons are mixed states produced by strong coupling between a vibrational mode and an optical cavity. Here, the authors show that these polaritons can coherently exchange energy and exhibit drastically altered transient spectra and dynamics compared to uncoupled vibrations.