Chiral emission induced by the interaction between chiral phonons and localized plasmon

Abstract

We demonstrate chiral photoluminescence and scattering induced by the interaction between chiral phonons and localized plasmon. In the experiment, we constructed a hybrid structure of single gold nanorods and bilayer graphene. The optical chirality was investigated with a helicity-resolved single-particle spectroscopy technique, including the dark-field scattering and photoluminescence spectra. The single-particle spectra can effectively indicate the chiral phonon in bilayer graphene. That is due to the interaction between achiral local surface plasmon resonance and chiral phonons, which influences the plasmon damping at the interface. We propose a plasmon–phonon coupled spectroscopy method for phonon chirality detection. This method provides an advantage for developing high spatial resolution detection of chiral phonon in low-dimensional materials due to the localization of plasmonic near-field.