Charge transfer at the plasmon-molecule interfaces controls the collective chiroptical responses

Area of Science:

• Plasmonics
• Chirality
• Molecular Spectroscopy

Background:

• Interactions between molecular excitations and metal plasmons are crucial.
• Understanding electronic excitation of chiral molecules at plasmon-molecule interfaces is challenging.

Purpose of the Study:

• To investigate chiral molecule-plasmonic nanoparticle interactions.
• To elucidate the role of interfacial charge transfer in chiral molecular excitations.

Main Methods:

• Construction of chemically-adsorbed, optically-resonant complexes.
• Atomic control over molecule adsorption on nanoparticle surfaces.
• Analysis of chiroptical responses and circular dichroism spectra.

Main Results:

• Interfacial charge transfer induces delocalized chiral molecular excitations and intermolecular couplings.
• Delocalization significantly impacts chiroptical responses (spectral shifts, broadening, intensity variations).
• Interfacial charge transfer's influence is dominant over near-field electromagnetic couplings.

Conclusions:

• Provides new insights into optical chirality at plasmon-molecule interfaces.
• Demonstrates the significant impact of interfacial charge transfer on chiroptical properties.
• Inspires quantum manipulation of chiral molecules for emerging applications.