Vibrational polariton transport in disordered media.

Chemical reactions and energy transport phenomena have been experimentally reported to be significantly affected by strong light-matter interactions and vibrational polariton formation. These quasiparticles exhibit nontrivial transport phenomena due to the long-range correlations induced by the photonic system and elastic and inelastic scattering processes driven by matter disorder. In this article, we employ the Ioffe-Regel criterion to obtain vibrational polariton mobility edges and to identify distinct regimes of delocalization and transport under variable experimental conditions of light-matter detuning, disorder, and interaction strength. Correlations between the obtained trends and recent observations of polariton effects on reactivity are discussed, and essential differences between transport phenomena in organic electronic exciton and vibrational polaritons are highlighted. Our transport diagrams show the rich diversity of transport phenomena under vibrational strong coupling and indicate that macroscopic delocalization is favored at negative detuning and large light-matter interaction strength. We also find the surprising feature that, despite the presence of dephasing-induced inelastic scattering processes, macroscopic lower polariton delocalization and wave transport are expected to persist experimentally, even in modes with small photonic weight.