Chemistry under Vibrational Strong Coupling

Abstract

Over the past decade, the possibility of manipulating chemistry and material properties using hybrid light-matter states has stimulated considerable interest. Hybrid light-matter states can be generated by placing molecules in an optical cavity that is resonant with a molecular transition. Importantly, the hybridization occurs even in the dark because the coupling process involves the zero-point fluctuations of the optical mode (a.k.a. vacuum field) and the molecular transition. In other words, unlike photochemistry, no real photon is required to induce this strong coupling phenomenon. Strong coupling in general, but vibrational strong coupling (VSC) in particular, offers exciting possibilities for molecular and more generally material science. It is not only a new tool to control chemical reactivity but it also gives insight into which vibrations are involved in a reaction. This perspective gives the underlying fundamentals of light-matter strong coupling, including a mini-tutorial on the practical issues to achieve VSC. Recent advancement of 'vibro-polaritonic chemistry' and related topics are presented with the challenges for this exciting new field.

Vibrational Coupling of Water from Weak to Ultrastrong Coupling Regime via Cavity Mode Tuning

“…In contrast, in the case of the strong coupling regime, the photon can mediate hybridization of the electromagnetic field to achieve energy splitting of polaritonic states. ,, As a result, observed Rabi splitting frequency is larger value than sum of photon loss rate and dephasing rate. Recently, polaritonic states have been used to transform ground-state molecular properties via formation of a vacuum strong coupling state. − This concept can also be applied to the vibrational states of molecules; placing molecules in a microscale cavity induces the vibro-polaritonic states, − which leads to modification of the ground-state thermochemical reactivity via vacuum vibrational coupling. − This vacuum vibrational strong coupling is also used to modify Raman scattering, , vibro-polaritonic infrared (IR) emissions, the self-assembly of molecules, , ferromagnetism, and even the superconductivity of materials . Recently, we also investigated the use of vacuum vibrational coupling to modify the proton conductivity of aqueous electrolyte solutions .…”

Generalization of the Tavis–Cummings model for multi-level anharmonic systems

“…23,24 Recently, there has been an increasing interest in the properties of vibrational polariton systems resulting from the strong coupling of infrared (IR) cavity modes and ensembles of localized high-frequency vibrational modes in molecules in condensed phases. [25][26][27][28][29][30][31][32] The multilevel anharmonic spectrum of these vibrational modes implies that their accurate description should invoke more than two levels per emitter. Indeed, consideration of more realistic vibrational SC systems involving anharmonicities has been the subject of theoretical explorations, such as the use of single-molecule models to explain cavity-induced modifications to chemical reactivity, [33][34][35][36][37] as well as the use of many-molecule models a) Electronic mail: joelyuen@ucsd.edu; http://yuenzhougroup.ucsd.edu to explain non-linear response experiments.…”

Chasing Vibro-Polariton Fingerprints in Infrared and Raman Spectra Using Surface Lattice Resonances on Extended Metasurfaces

“… 3 Notorious examples are sensing, 4 lasing, 5 − 7 exciton diffusion, 8 − 10 charge transport, 11 , 12 energy transfer, 13 , 14 and catalysis. 15 − 17 …”