Decoupling from a Thermal Bath via Molecular Polariton Formation

Abstract

The coupling between an electronic system and an environmental bath plays a decisive role in the excited state dynamics of artificial/natural molecular condensed phases. Although it is generally difficult to control the coupling between the system and the thermal bath in condensed matter, a strong light–matter coupling can control system–bath coupling properties using the polaron decoupling effect, in which a coherent interaction between excitons and photons reduces the reorganization energy. Here we demonstrate that this polaron decoupling strongly reduces the fluctuations in electronic energy in tetraphenyldibenzoperiflanthene thin films embedded in an optical microcavity. Using two-dimensional electronic spectroscopy, the frequency–fluctuation correlation function of the lower polariton state was revealed, showing that the dynamic inhomogeneity due to bath coupling inside the microcavity almost vanishes completely. This was attributed to a significant delocalization of the lower polariton state over 105 molecules in the cavity, reducing the effective coupling strength of the bath modes.

Multi-scale dynamics simulations of molecular polaritons: The effect of multiple cavity modes on polariton relaxation

“…We speculate that this anti-Stokes emission is predominantly caused by the relatively large energy fuctuations when small systems, like ours, are simulated at constant temperature. Therefore, even if anti-Stokes emission has been observed experimentally at the minimum of the lower polaritonic energy branch 75,76 as well as emission from the UP at elevated temperatures, 27 we consider the photo-luminescence at the higher energies and k z -vectors observed here, a fnite size effect due to relatively large energy fuctuations in the small simulation systems, and hence do not consider this further.…”

Engineering the Aggregation of Dyes on Ligand-Shell Protected Gold Nanoparticles to Promote Plexcitons Formation

“…The formation of plexcitons has been extensively studied with metal surfaces endowed with propagating surface plasmon polaritons (SPPs) [ 29 , 30 ], and it was recently extended to the localized surface plasmon resonances (LSPRs) of metal NPs in solution [ 31 , 32 , 33 , 34 ]. Interest in plexcitons is justified by the possibility of controlling the matter properties just by acting on the light–matter coupling, enhancing the efficiency of relevant reactions such as energy and electron transfer [ 35 , 36 ], and reducing the interactions with the environment [ 37 ]. These features are promising for important applications in artificial light-harvesting, sensors, and photonics [ 25 , 26 , 28 , 36 , 38 ].…”

Molecular Polaritons Generated from Strong Coupling between CdSe Nanoplatelets and a Dielectric Optical Cavity

“…13 These phenomena have been primarily investigated by forming molecular polaritons through coupling organic molecules with optical cavities. [12][13][14] However, funda-mental limitations of using organic molecules for generating polaritons are their short lifetime of electronic excitations and their relatively small transition dipoles that limits the magnitude of light-matter interactions.…”

“…In addition, there is a dense manifold of states in between these two polariton states, which have predominantly electronic character, known as dark states . Transitions between the dark states and the bright states induce rich polariton photophysics and novel quantum effects, such as enabling polariton lasing, facilitating an exciton-polariton Bose–Einstein condensate, or decoupling the electronic states from phonons, − thus significantly enhancing the electronic coherence lifetime . These phenomena have been primarily investigated by forming molecular polaritons through coupling organic molecules with optical cavities. ,, However, fundamental limitations of using organic molecules for generating polaritons are their short lifetime of electronic excitations and their relatively small transition dipoles that limit the magnitude of light–matter interactions.…”