  In plasmonic chirality, the phenomenon of circular dichroism for achiral
nanoparitcles caused by Coulomb interaction between metal nanoparticles (NPs)
and chiral molecules have been studied. At the same time, under the resonance
condition, the dye molecules and metal NPs will produce huge Rabi splitting due
to strong coupling. If the chiral molecules are at the resonance of the
plasmon, what will happen for the strong interaction between the plasmon and
molecules with chirality introduced? In this paper, we investigate a spherical
core-shell model and analyze its spectral phenomena under the excitation of
circularly polarized light (CPL). Based on Coulomb interaction between NPs and
chiral molecules, we will show how the various factors affect the strong
coupling. We have obtained three mechanisms for the interaction between
plasmons and chiral molecules: strong coupling (Rabi splitting up to 243mev),
enhanced absorption and induced transparency. The interaction between CPL and
chiral molecules with the opposite chirality to CPL is stronger than that of
the same chirality, and the line width of the two peaks is closer than that of
the same chirality, which shows that for the Rabi splitting with chirality,
there are deeper mechanisms for the interaction. This result will be helpful
for further research on the interaction between plasmon and molecules with
chirality.
