Inherent Promotion of Ionic Conductivity via Coherent Vibrational Strong Coupling of Water

Hydrogen bonding interactions among water molecules play a critical role in chemical reactivity, dynamic proton mobility, static dielectric behavior, and thermodynamic properties of water. In this study, we demonstrate the modification of ionic conductivity of water via hybridization with vacuum electromagnetic field by strongly coupling O–H stretching mode of H2O to a Fabry–Perot cavity mode. This leads to formation of collective vibro-polaritonic states which, as experiments show, enhances the proton conductivity does increase by an order of magnitude at resonance. In addition, an increase of dielectric constants is observed at resonance in the coupled state. Our finding illustrates that the potential of engineering a vacuum electromagnetic environment to control the ground-state properties of water.